The early R65s were not that popular and some parts are a pain in the butt to get. Very few of the R 65 parts are interchangeable with the more popular R/bikes.
I don’t know what city you are in, but join the Airheads. I am a member and we live for traveling to get together and work on each other’s bikes. And camp and drink beer. airheads.org
This is my 1976 R75/6.
