I'm definitely familiar with that phenomenon -- for example, I know "Minnie the Moocher" was originally much, much longer than the standard version that's always performed. This is a bit of a different situation, though. I can't even find a whole chorus (let alone any verses!) for either the original "Burlington Bertie" (which is a totally different song from "Burlington Bertie from Bow") or "Bertie the Masher" . . . just a few excerpted lyrics here and there. Both seem to have fallen into obscurity. I know there is sheet-music for "Burlington Bertie" out there, but it's pretty rare. I'll have to see if I can snag it through ILL.