Steve's gun is a Beretta M9 that has not been invented until the 1980s.
In the bar/brothel scene at the start of the movie a soldier is wearing two different ranks. He has a specialist (E-4) insignia on one sleeve of his uniform and sergeant (E-5) stripes on the other sleeve.
During the dream sequence flashback to New York City, the second image of the sailboat going by has matting over the bottom of the image for 2 frames, either from bad splicing or cropping of the stock footage.