Who has rebuilt a '68 A-body heater box with A/C

I finally dragged out the old heater/AC box and started inspecting it for reconditioning. Pheeeewwww! Vacuum hoses, cables, doors, rods, linkage, switches, ballasts, you name it....everywhere!!! And just about every piece of fiberglass/plastic is cracked or crumbling. I assume that many of the parts are available for replacing the old worn out crap, but to be on the safe side, I would want to replace all the vacuum diaphragms, switches, etc. I'm thinking that I might end up building a whole new system one piece at a time. To be honest, I am much more comfortable working with heavy pieces of metal than I am with little DC motors and vacuum controls.

Who's done this before? Was it as daunting as it looks to little ole me? I'm almost inclined to go to the "parts wanted" forum and look for one already done.