Best A- Body Brake Booster Rebuilder

Ok...need some recommendations and help. My B-Body brake booster is being replaced with an A-Body brake booster. Where do I send this ratty looking, very rusted assy so it comes back working and nice appearance???. I believe the factory Zinc coated the firewall bracket and bellows chamber. Also do I spray clear coat on the chamber so it does not "become" white and the Zinc wears off??? Some of my friends have a"ratty" appearance on ther big block MOPARs and suggested chrome (big $$$$$$ and not original on a simple SL-6).

Thx...Happy MOPAR driving..long live Dodge Darts and SL-6.