It looks like a regular production board with some wire mods. It has some production EPROMS, with some others that look somewhat like they might have 'revision' Eproms in it. Who knows, but it's probably just the final code. A prototype board would most likely be a light, translucent brown/green color with all three processors populated. You can see all of the inspection stamps that Solectron used, when they built boards for Atari.