Jaycoop,
Check NAPA, they may have your booster. Or try Precision Rebuilders at
http://www.precisionrebuilders.com/about_us.html. I would guess the cost to rebuild an air vs vacuum booster would be about the same $200-250 range. Don't forget to replace ALL of the hydraluic parts while you're at it (steel and rubber lines, reline shoes if needed, wheel cylinders and master cylinder). The lines will fail from the inside out. The entire project might set you back about $800-900, but being safe is worth WAY more than that!
Mike B
