Disaster

check for water or foam damage from attempts to put out the fire too

the real question is whether the ins. co. will pay willingly for repair, which will likely be more costly than replacement for a vintage system that ir irreplaceable - I hope you have an uncle who is a lawyer

can you post a list of what the gear is?

I suspect each item can be replaced with time-consuming searches and then re-modified.

Back to cleaning - some firm cleans museum pieces after fires cause soot, water & foam damage, so it should  not be impossible.

A thorough inspection will be needed.

Good Luck!

if the room is large enough it could maybe be rebuilt with a false front wall - like a recording studio to eliminate baffle effects

you can certainly do some things to deaden the walls too