Here's a picture of the phony gun:

Dillinger must have had balls the size of church bells to pull a scheme like this - that gun wouldn't fool anyone who looked at it for even a second. I'm no gun nut, but I don't think the words "colt 38" are normally actually written on the side like that. According to most versions of the story, no one really SAW it - Dillinger stuck it in a guard's back, said "stick em up!" and soon had acquired several REAL pistols from the guards.
The alley where Dillinger was shot is now between two Mexican restaurants and features of a mural of a guy playing a guitar. Until its recent touch-up job, the painting always made me want to say "hello, my name is Inigo Montoya. You killed my father. Prepare to die." Here it is, pre-touch-up:

Incidentally, if the cast of "Public Enemies" would like a tour, we'd be happy to oblige :)