No problem, you tried to help and it is still appreceated ! I too had too learn (and still have) a lot. Hope RayB can put up some pics.
That coin mech you have has a serial and a parallel output. I think it's a bit overkill for a MAME cab, but I guess it came with the cab ? No idea if it simply outputs a contact when a coin is accepted, but I actualy don't think so. So a hook up to the PC would mean serial (RS-232) or other fancy connecting. Guess you don't want/need that.
But I could be wrong. It is programmable, and I've seen people offering to program it for 39 euro. I bought two mechanical coinproofs for that money, but of course, these are less flexible...