Now that the altered Hobbit text has been the standard for over 70 years, it’s strange for the modern fan to come across passages in LOTR concerning Bilbo’s lying about the Gollum encounter when the only take we have is the “truthful” version.
But that wouldn’t be the last time Tolkien attempted to tweak The Hobbit. In 1954, he wrote “The Quest of Erebor” for inclusion in Appendix A of LOTR. This reframes the setup of The Hobbit from Gandalf and the dwarves’ perspectives (retold by Frodo) and connects it directly to the bigger picture struggle with Sauron. Gandalf met Thorin Oakenshield in Bree and discussed their upcoming quest. Gandalf wanted to remove Smaug from the board so Sauron couldn’t use him as a weapon, and Thorin wanted him out of the Lonely Mountain so he could reclaim his rightful dwarven treasure. Ultimately, this didn’t make it into the appendix due to space limitations but was eventually included in The Unfinished Tales of Numenor and Middle-earth in 1980.
In 1960, Tolkien embarked on a wide-ranging rewrite of The Hobbit on a similar scale to that of the “Riddles in the Dark” chapter all those years before. This project aimed to draw the book completely in line with LOTR in both connecting tissue and tone. In this version, gone is the whimsy and narrator asides to the (presumably young) reader. Gandalf is more stern and authoritative and Thorin is more abrasive and treasure-obsessed, which makes his later case of dragon-sickness less of a contrast to his normal demeanor. In both this rewrite and the earlier “Quest of Erebor” appendix entry, Bilbo is generally painted as more foolish, unfortunately.
Once Tolkien had reached the beginning of Chapter Three in his rewrite, he sought the opinion of a close friend (whose identity remains a mystery). The feedback he received boiled down to “This is wonderful, but it’s not The Hobbit.” He ended up dropping the project afterward and kept his revisions for the Third Edition in 1966 to corrections and smaller tweaks.