Hey shardian,
I don't think I'd call it "good" cosmetic shape, it may be a "solid" cabinet but that pink is faded big time on both the cabinet and marquee!! $100 for that game would be a generous offer IMO. If I had it I'd have to turn it into a Galaga because it'd be so much easier and cheaper than trying to make it a nice MsPac. That's really cool that you actually tried to contact them and snapped some pics.

Willis made all kinds of replacement art in the 80's, I'm kinda surprised you don't know all about this already. Usually they are uglier and cheesier than the factory stuff, but there are two CP's that I kinda like better. The Jungle Hunt/King overlay is pretty cool, and the Centipede is definitely cool. A LOT of the other ones are just butt ugly.
Wade