Pretty sweet, Sadler! Are you sure it's a converted Galaga '88 cabinet? The layout is wrong from the ones I've seen (button layout, monitor orientation, and speaker location), so maybe it's an original cabinet that was originally set up as a Galaga '88 huey.
Well, I've spent some time trying to figure out exactly what I've got on my hands. It doesn't help that I know nothing of arcade games, but I've found some interesting stuff. First, here's a link dump:
neo-geo forum thread with great picsManual for hardwarePCEFX thread from some guy that apparently got some portion of the hardware
Most recent PCEFX thread
To address the cab itself, you are right, I don't think this is a Galaga '88 cab. Google image search doesn't show anything like what I've got. What
is clear though, is that at least some of this is the United Amusement stuff (more speculation on this later). Compare the controller in these pics:
to my controller:
The button layout is the same, apparently left/right handed? My controller has a green stick, but that seems pretty minor. My marquee doesn't seem to match the marquee in those pics though.
Anyway, moving on to United Amusement. Anyone know more about these guys? The Galaga sticker on my cab reads "United Artists Theatre Amusements". Is the similarity in name just a coincidence?