Nathan Natas, myself and no doubt countless other children studied the LGBT book in the 1940/50's. There was an interesting QFR asking why the WT Society did not produce a book for children. The reply in part, is shown below.
George
Questions From Readers June 15, 1952
● Why does not the Watchtower Society publish simplified material for parents to use in teaching their children Bible truths?—A question based upon frequent inquiries by readers.
It is also true that when the Law covenant ended and Christianity was established provision was made for a new priesthood to minister to the needs of obedient peoples, including an organized “faithful and discreet slave” class today that is commissioned to “give them their food at the proper time”, spiritual food here being meant. (Matt. 24:45-47; Heb. 3:1; 1 Pet. 2:9; Rev. 20:6, NW) But from this we may not argue that the “faithful and discreet slave” class must publish special books for children. The priests in Israel did not write special scrolls for the children to study. God’s Law did not provide for special tutoring of children groups separated from adults. Young and old were to assemble together for instruction. (Deut. 31:10-13) It is the same today. The “faithful and discreet slave” serves the spiritual food and arranges for congregational meetings of various kinds to make it available to all, young and old together. Then just as the parents in Israel had to fix these things in their minds so they could later impress them upon their children, parents today must simplify and clarify the truth for their children. Neither the priestly instruction in Israel nor the “discreet slave’s” provision for the theocratic organization today was or is for children exclusively.
None of the sixty-six books of the Bible were written specially for children. From infancy Timothy was taught by his grandmother Lois and his mother Eunice, not from some child’s study book, but from the Holy Scriptures. (2 Tim. 1:5; 3:15) The typical theocracy in Israel provided no simplified study material for children. Neither was such provision made in the days of Jesus and the apostles. None need be made now. Adapting the material to the child’s mental capacities is the parent’s assignment from God. It is good for the parent. It will make the parent a diligent student himself, for one’s knowledge must be thorough in order to explain clearly and simply to others.