Need sources for parts for a 75 Argosy

We are excited about our recent purchase of a 1975 Argosy Airstream 26' motorhome. The motorhome is equipped with the great 454 engine. We are working with it as a part of a show that will be highlighting the restoration, renovation and subsequent lifestyle of the "Airstreamer!" We are working with a mechanic in Florida who is having trouble finding parts for the mechanical restoration. The parts he really needs are all the belts and hoses, parts for the brake system, coolant system, etc. He said that the air intake and the cooling system were modified and I am not sure whether he meant that was done by Airstream or by someone after market. We really would like (and need) assistance finding sources for these parts and any information on that year make and model of Argosy Airstream?? Can anyone help us? We would so appreciate the input. We can't wait to get it on the road and meet some of our fellow "Airstreamers"! Thanks, Robert