Oh, ha... now that I'm not on Tapatalk I can see the Moon Patrol screenshot
I wouldn't think you have to replace any, just supplement in parallel. If you look at the 16-bit era, 10uF (Sega / Pioneer) through 22uF (NEC) were typical values for bypass caps. Again I'm just kind of "writing out loud" here and haven't tested any of this, except for adding caps to the RAMs themselves. There could be other loop issues present due to the twin 7805s design. According to the schematic, the RAMs and ANTIC/GTIA aren't even fed by the same regulator.