Revealing mistake: During several scenes, the street lamps are the mercury vapor type which were not used in the 1960's.
Revealing mistake: When C is rolling dice with all the guys, Jojo the Whale keeps trying to get a better view and keeps breathing on Sonny which gets Sonny mad. In one of those shots, you can see Jojo look up at someone in the production crew, behind the camera view and as if on cue, start to get close to Sonny and get him mad again. There is nothing behind the camera that's shooting the shot except a wall.
Answer: $20; C gave up trying to collect after Sonny convinced him that it wasn't worth the effort since the "friend" wasn't really that close to C in the first place.
zendaddy621