The first edition of the KIT was released in 1969 with a woefully inadequate printing run. Just half a million copies to serve the then one and a half million WT followers. The "brothers" were told not to take more than a single copy per family.
In 1985, a second edition was published, again with a woefully low printing run. Just eight hundred thousand copies for the whole WT population of 5 Mill. The fact that the printing runs were so low is an indication that the WTS was not really serioius in placing these copies with each Witness in their congregations, let alone with the public at large.[Compare this with the nearly 40 mill publishing run for the NWT] It appears more to be a veneer indicating either to the ignorant or the credulous that the WTS does indeed have adequate NT backing for their idiotic renderings.
The text of the two editions are virtually identical except for the following:
1 For some reason the ' 85 edition stands half an inch shorter, and is more a pocket sized edition.
2 The cover has standard gold leaf embossing, while the earlier one has italic embossing
3 The earlier edition makes use of 21 "J" documents for their "Jehovah" renderings in the NT, while the " 85 edition has 27 such "J"s Not that this makes any difference since these are merely Hebrew translations of the Erasmus TR NT text, which the JWs do not endorse. [Particularly because of the Johannine Comma at 1Jo 4:8]
4 The only change in the text itself is to change the interlinear translation of "Theothes" at Col 2:9. The original had "godship" [small "G"] this has been changed to "divinity" [small "D"]
5 The major change is in the explanations given in the Appendix section. The original ' 68 made pompous remarks about no archaeological evidence for a transverse crucifiction in Bible times. Promptly a report was published in Newsweek and Time magazines telling of the finding of a tomb of a man who, in Bible times WAS indeed crucified in the transverse position. So the offending statement has been quietly excised from the second edition. Other adjustments in the Appendix have also been needed.
The Emphatic Diaglott no longer belongs to the WTS, the copyright having expired in 1982. It is now available in the public domain and various sites, such as "Online Bibles, North America" have it for free download.
Cheers