I found two sources for some things, but with these old bikes, its hit-or-miss. Try Phil at Cheyenne Motorsports in Montana (no website, but he has an e-mail address which I don't have at the moment). Call 411 to get a phone number. He was a provided info and advise for my old machine.
Also try Motorcycles Unlimited in Abilene TX. (325) 548-2458 or
www.motorcyclesunlimitedtx.com. His website lists parts by part number. He had some new O.E. out of production rubber pieces to fit my bike at a great price.
Both shipped parts to California.
Good Luck!