Giff Me - - Was Larry correct or was he exaggerating? I noticed in the book, Stooges Among Us, that Larry said they did ad-lib and said that they did not. I think some of Larry's answers depend on when he was asked and his health at that time, and also the effects of aging. Memories are not static for anyone. That's one reason eyewitness accounts of crimes are suspect. Memories are also able to be influenced by suggestion and life experiences, among other things. So maybe in both cases, whether talking about sets or about ad-libbing, Larry gave his best recollection at that moment. Also, consider that the Stooges didn't try to memorize every iota of information about each short anymore than anyone does that when working.
Metaldams - - I just saw some movie where I heard commentary saying that the train set in the movie was the same one used in that Stooges short (I wasn't watching "Twentieth Century"). I wish I could remember what it was!
Movie studios also rearranged and redecorated sets according to need, as you know. That's how the "Petticoat Junction" train interior could also serve as the "Wild Wild West" train interior. So maybe there are lots of movies where we've seen Stooges' sets but we just don't know it. Sometimes I recognize costumes from one movie to another if the costumes are distinctive.