NOS Booster, use or rebuild?

Howard1784 said
My question is, would you bolt on the NOS and see what happens or hold off; send it out for a rebuild

Just apply vacuume to the vacuum port. Draw up to 15 inches and let it sit. If it holds that's a good sign.

As for the other parts inside I suspect grease would be dried up, rubber might be dried out etc. worst case is you have to unbolt it and send it out.