I was watching this too as I happen to have a spare US spec (spinning disk) complete head box.
It is not easy to find the sound/speech card, but they are around from time to time, but are also subject to the amp failing (although Homepin makes a great drop in replacement that I used on Haunted House). I'd expect these would sell for about $150 plus shipping and exchange - maybe $200.00 if you find one. Drop in with the right ROM and speech is added.
Great info thanks for sharing.
