Hey Blondie, I found the November 1 1947 wt on pages 324-331 (study article with lots of references to "field service") being referred back to the "rule of love" and quoting Matt 7:12. For example:
38 "It is God?s teaching that we love one another, and that we love our neighbor, and God is the great "King of Eternity". This is a royal law that he gives us for our guidance in this day of selfishness that has run amuck. We shall not go wrong if we follow it and apply it practically and with sincerity and genuine affection. "If ye fulfil the royal law according to the scripture, Thou shalt love thy neigbbour as thyself, ye do well." (Jas. 2: 8) Growing out this royal law are Jesus? words: "Therefore all things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets." (Matt. 7: 12) This leaves no room for partiality, especially partiality toward our own selves. No partiality should be shown toward a Kingdom publisher or minister who reports many hours afield in service as against another who reports less but who is just as eager and earnest to serve the most High God. As servants or slaves of one another in imitation of Jesus Christ, we will encourage all the brethren into that public confession with the mouth that wins divine approval and leads to their salvation. We will not be partial toward one nationality or race as against another, but will discern them all to be our neighbors if they are kindly disposed to the Lord and anxious for salvation that emanates from Him through Jesus Christ. We will love our neighbors of whatsoever nation, kindred, race and tongue, and we will therefore be moved to share with them the message of salvation which the neighborly love by others has passed on to us ourselves.
So my laic interpretation is that by this time (1947) the Rule of Justice (Golden Rule) became the Rule of Love - and a support scripture to peddle magazines.
Glen