maybe I missed it, but was the amp on... I know you said the power valves were fried, but how do you know? did you check them?
since I repair my own amps, I can say this, but I'd pull the amp apart... totally. gently clean the boards and chassis with mildly soapy water, rinse and let it dry thoroughly. Then take it to a amp tech and have him put it together check it out. It may end up only requiring a revalve. Hopefully the fuses saved the amp.