Brake Booster Help Needed.

[Swbman]

I need to replace or repair my brake booster in my 3/4 71 burb (because of engine compartment fire). I opened mine up and seen that the 11 inch round rubber diapham got baked to a crisp,nothing much to rebuild it of which I would prefer to do but finding a rebuild kit for it is proving to be difficult,has anyone built theirs and if so where did you get parts for it.If I cant get parts for it Ive have couple of boosters from 1/2 ton trucks but they much thinner than the one from my 3/4 ton,does anyone know if thats going to make a difference in braking power,I can get a rebuilt one locally for 119.00 plus core but Im like why pay someone for something I can do myself especially now since Ive got the dang thing all a part.