John....I concur that the Pauline correspondence has been interpolated in quite a few places and includes pseudepigrapha (e.g. 2 Thessalonians, Ephesians, the second-century Pastorals), but I am persuaded more by the analysis of Doherty and Wells (who view the correpondence as the oldest Christian texts) than by Price's more radical view, designating the corpus Paulinum as Marcionite compositions. As for the Gospel of Luke, I agree that it was a work-in-progress for quite some time (like the Gospel of Mark, which evidently went through several editions, and Matthew which was the main source text for the Gospel of the Hebrews), but I think it is too simplistic to regard Marcion's gospel as the original -- perhaps "more original" and closer to the earlier editions of Luke, but doubtlessly containing Marcion's own redactional and literary work as well. In other words, the original (if we can even speak of an original) stood somewhere between Marcion's version and the canonical one. I fully concur that the earlier versions were more docetic; a most clear example is the corporeal resurrection appearance in Luke 24:36-43 which obviously corrects the patently docetic appearance in 24:28-33. The promise to the thief in Luke 23:43 also assumes an immediate assumption at death and not a corporeal resurrection. But docetism was not a monolithic belief and there is a difference between docetism of Marcion, wherein Jesus always had only the semblence of flesh, and the docetism of Cerinthus, who regarded the Heavenly Man as filling a fleshly vessel (a real human being) during his earthly life and continuing as a spirit after his departure:
"Cerinthus ... represented Jesus as having not been born of a virgin, but as being the son of Joseph and Mary according to the ordinary course of human generation, while he nevertheless was more righteous, prudent, and wise than other men. Moreover, after his baptism, Christ descended upon him in the form of a dove from the Supreme Ruler, and that then he proclaimed the unknown Father, and performed miracles. But at last Christ departed from Jesus, and that then Jesus suffered and rose again, while Christ remained impassible , inasmuch as he was a spiritual being. Those who are called Ebionites agree that the world was made by God; but their opinions with respect to the Lord are similar to those of Cerinthus and Carpocrates. They use the Gospel according to Matthew only, and repudiate the Apostle Paul, maintaining that he was an apostate from the law . As to the prophetical writings, they endeavour to expound them in a somewhat singular manner: they practise circumcision, persevere in the observance of those customs which are enjoined by the law, and are so Judaic in their style of life, that they even adore Jerusalem as if it were the house of God." (Irenaeus, Against Heresies 1.26.1-2)
This is an adoptionist christology viewing Jesus as a natural man who between his baptism and death was used as the recepticle of the divine Christ. The Gospel of the Ebionites presented a similar adoptionist view by having the Holy Spirit "descend and enter into" Jesus at his baptism (GEbi, fr. 4). The apologists similarly characterize the Ebionites as believing that Jesus was "a man in a like sense with the rest of the human family" but who was the first to "observe completely the law" (Hippolytus, Against All Heresies 7.22), "a plain and common man, who was justified because of his superior virtue, and who was the fruit of the intercourse of a man with Mary" (Eusebius, Ecclesiastical History 3.27), "begotten by Joseph" and "natural birth" (Irenaeus, Against Heresies 3.21.1; 5.1.3), "a bare man, merely the seed of David" and "born of human seed" (Tertullian, De carne Christi 14, 18), "begotten like other human beings" (Origen, Contra Celsus 5.61), and so forth, and Eusebius distinguished between Ebionites who simply believed that Jesus was a human prophet who was saved from death and others who believed that the Lord also pre-existed as Wisdom and Word and came upon Jesus. The Ebionite Ascents of James similarly has two recensions, an earlier one where Jesus is simply the True Prophet "foretold by Moses" who teaches how to "follow a perfect life" in the Torah so that people may "abide in immortality" and "be kept unhurt from the destruction from war which impends over the unbelieving nation" (a concept quite akin to the Qumran "Teacher of Righteousness"), and a later recension which designates Christ Jesus as "a man to rule over man," just as in nature there is a fish to rule over the fishes or a bird over the birds, who "in the waters of baptism was called by God his Son" and "by which the priesthood or the prophetic or kingly office was conferred," just as "Arsaces among the Persians, Caesar among the Romans, Pharaoh among the Egyptians, so among the Jews a king is called the Christ", through whom the "Son of God and the beginning of all things ... became man" (1.39, 45). This kind of adoptionism, strikingly similar to the type described by Hippolytus, also appears in muted form in Hermas of Rome:
"The preexistent Holy Spirit, which created the whole creation, God caused to live in the flesh that he wished. This flesh, therefore, in which the Holy Spirit lived, served the Spirit well, living in holines and purity, without defiling the Spirit in any way. So, because it had lived honorably and charitably, and had worked with the Spirit and had cooperated with it in everything, conducting itself with strength and bravery, he chose it as a partner with the Holy Spirit, for the conduct of this flesh pleased the Lord, because while possessing the Holy Spirit it was not defiled upon the earth. So he took the Son and the glorious angels as counselors, in order that this flesh also, having served the spirit blamelessly, might have some place to live, and not appear to have lost the reward of its service. For all flesh in which the Holy Spirit has lived will, if it proves to be undefiled and spotless, receive a reward" (Hermas, Similtude 5.6.5-7).
There were thus early Christians who believed that Jesus (or in Hermas, the fleshly recepticle of the Spirit) was born in the flesh and had a corporeal existence but did not subscribe to the proto-orthodox belief in the incarnation, or that the Revealer himself had any fleshly body of his own. Then there were Jewish-Christians who didn't view Jesus as a heavenly being figure at all, but who thanks to his fidelity to the Law was saved from death and (like the faithful men of old like Abraham, Isaac, and Jacob) was given a place in Paradise to live. The view in Hermas and the view attributed to Cerinthus by Irenaeus would thus seem to be a compromise between the more pure Heavenly Man belief of Marcion and the Jewish-Christian view of Jesus simply as a human prophet foretold by Moses (a view which survives in Islam, which drew on Jewish-Christian sources), possibly representing the same return of the divine Wisdom of God to human prophets as we find promised in 1 Enoch, Qumran texts, and other sources. I regard both as components of early Christianity and suspect that Doherty and Price might be too "Paulocentric" or "Marcion-centric" in viewing the entire movement as stemming from the Hellenistic mysteries, which do not explain the nature and texture of Jewish-Christianity. I suspect something more complex was afoot: that Christianity represented the convergence of a first century Nazorean movement, centered on a new way of interpreting and practicing the Law (whose eponymous founder was believed to have restored the true way of following the Law, who perfectly followed the Law, and who was rewarded from death by assumption into Paradise to dwell with Abraham, Moses, etc.), and the proto-gnostic movement of Paul and others who added the whole notion of the Savior being heavenly, judged, crucified, glorified, etc., and thus the later gospel tradition, Cerinthus, proto-orthodoxy, Ebionites, and others combined these originally independent streams of tradition in different ways. That would explain why the earliest documents in the Jewish-Christian Nazorean tradition (i.e. Q, and the earliest strata of the Didache) show no familiarity with the suffering and Passion of Christ and have no concept of the ransom-redemption doctrine that was the whole heart of Paul's gospel, and why Paul resists the whole idea of Nazorean/Ebionite practice of the Law in Romans and Galatians but adopts their moral teaching in certain sections of Romans and 1 Corinthians. The Nazorean movement may not have had any single founder, or perhaps it was a vague "Teacher of Righteousness"-type figure, or even (borrowing the suggestion of Price) the founder (or late leader) was John the Baptist, and his martyrdom at the hands of the authorities was the key locus where Hellenistic mystery traditions of a dying-rising Savior glomed onto the very different traditions of the Nazoreans.
Going back to the Gospel of Luke, my opinion is that -- in view of Luke 23:43 which has Jesus going to Paradise on the same day as his death, Luke 9:28-26 which expands the Markan transfiguration scene to have Moses and Elijah (two prophets who also ascended to heaven at death) discuss with Jesus his upcoming "departure in Jerusalem" (v. 31), Luke 13:22-30 which uniquely has Jesus describing "Abraham and Isaac and Jacob and all the prophets in the kingdom of God", Luke 13:33 which also uniquely implies that he himself would be the "prophet" perishing in Jerusalem, and especially Luke 16:19-31 which explicitly describes the faithful man in death being lifted up into the "bosom of Abraham" to be in fellowship with Abraham -- my opinion is that the older strata of Luke designate Jesus as a prophet who, as in the Ascents of James and the "righteous flesh" of Hermas, was saved from death, taken into heaven to the blessedness of association with Moses, Elijah, and Abraham, and thus "abides in immortality". The Life of Adam and Eve, Testament of Abraham, the Testament of Isaac, the Testament of Jacob, the Assumption of Moses, and the Apocalypse of Zephaniah all attest such a fate for the prophets and even King David. Note that it is just this view, that Jesus' body rotted in the grave while Jesus ascended to heaven like David and the faithful of old, that Acts 2:24-34 strenuously tries to disprove (without understanding that such ascensions occurred without the body). The Gospel of Peter, which has a form of docetism similar to Cerinthus, incorporates the resurrection and three-day motifs from the developing Passion tradition, but varies from the orthodox gospel narrative of the Resurrection in an interesting way: the Lord is "taken up" (the same verb that is used of Elijah in the LXX of 2 Kings, and of Jesus in Acts 1:11) while Jesus on the cross cries out "My power, my power, you have forsaken me" (5:19), then the "body of Jesus" was sealed up in the tomb and three days later two angels came down from heaven and took Jesus out of the tomb (10:38-43). Thus the Lord and Jesus are distinguished, with the Lord leaving Jesus at his death and Jesus being raised separately three days later.