XTC wasn't around til '92 (100b). Could be a Bogner modded Marshall or something similar, and while I agree it has a bit of that tone, that could be any number of amps.
The guys in Cinderella are well known for owning/using a fleet of real vintage Marshalls. They've always been considered by other touring guitar players as having some of the best tones on the live tour circuit.
That said, I have no personal knowledge of what amp Tom Keifer was using in that particular clip but I'd honestly be surprised if it didn't have a Marshall logo on it.