So I found a boxed NEC PC Engine RX that I can snag for 160 locally. It doesn't have any other packaging or instructions, just the system sitting in the box. Everything to get started except the A/V cable.
Right now I'm trying to find a cable so I can test the thing. I found a local store that has a A/V cable for a SuperGrafx. Does anyone know if they used the same cable through out all those different models? Also, I think I read somewhere I can use a Sega Genesis A/V cable, it just wont be in stereo.