They always had a stand-in geetar player for the close ups.
the piece he played on the street was actually played on two guitars.
Here's one from: If I had a Quarter Million; They never showed the Safe that Andy talked about. I guess they had it in the back room. Andy mentioned it a couple of times. He said he was gonna lock the suit case up in it. Then later - when he noticed the case was missing he said: 'Only Barney knows the combination to that safe' when he and the real FBI agent were in the courthouse. Also-- I always thought that if some criminal had dropped a mickey finn to my deputy and put him to sleep well I sure would have taken him down to the doctor to make sure he would be alright rather than just covering him up with a blanket and saying: " Sleep it off, tiger:" That's just me I guess. And also: what a wicked twist of fate the old hobo would have had if he had known that only about twenty feet away from his little camp across the rail-road tracks was a suit case loaded with serious dough. Or that what if the hobo had decided to camp on the other side of the tracks that night then he would darn near caught that suitcase in his lap when the bank robbers tossed it. Because they made the heist, but they blew the scram- a - voo.
I would bet it was Ernest T Bass that threw that extra rock!