The most recent game music I have by him is on my "Hong Kong Mahjong 2000" disk. The music wasn't written in 2000 though, by a long shot. The disk is updated from 1995, and who knows when The Fat Man composed the music. There is at least one theme on there that I recognized from Ultima Underground II.

Incidentally, Hong Kong Mahjong is an excellent tutorial for learning to play the real game, not the tile-matching version. I was able to complete with the hostesses on the Yangtze River cruise ship, just from learning (and practicing!) with the game.