My vote is get it running. Other than a monitor is looks like its in decent shape. The inside bottom looks a little odd? Was it wet or is that just the picture?
Looks like all is there, bezel looks OK as does the marque below the CP. That CP looks great. Those things are silk screened and tend to wear off easily. Yours still has the wording to the left, the direction arrows around the stick, and good looking black boxes drawn around the different sections of the CP art. All the cards are still in the cage. There should be a power supply board up on one of the walls.
Monitor wise, as mentioned, any standard res raster. Mine has a good old WG k4600 in it.
If you decide to do the deed and MAME it I would be interested in the parts. It would break my heart to see it parted since its all pretty much all there and in decent shape but, again, I would be interested. I have a buddy with a converted Gorf in his building now. I would probably just go get it and rebuild the parts on that cab.
On that topic, where are you located? If you are close enough getting you a cab for a conversion is not a problem for me. Perhaps we can work a trade. Just tell me what kind of cab you want.