I thought his name was Larry 'Bud' Melman up until I just read your post! I use to watch Letterman all the time and just figured that was his name.
Why wasn't Larry "Bud" Melman just introduced as Calvert Deforest? (That's actually a rather catchy and unusual name - so it would have worked for a quirky and unusual character). And why give him the nickname of "Bud" when Larry Melman wasn't even a real name to begin with? (I guess giving a fake character a fake nickname just helps complete the illusion that he's real.)
Like I said with Super Dave Osborne - why did he need an alternate identity when he already had a cool-sounding name: "Super Bob Einstein"?