[Brian]

I'm in New Zealand, so unable to assist you in advising where to purchase rebuild parts. Let me tell you this...sign of the times...I too had trouble sourcing these components which were so readily available in years past. Everything today seems to just be catering for the throwaway society...people no longer rebuilt stuff, merely replace their worn out 'old' stuff with the latest and greatest new version.
My latest 'issue' with this job is the brake linings the franchised brake specialist bonded onto the shoes I supplied. Some sort of black lining, very dusty, and the dust sort of smears over the lining as a crusty glaze. I've sent them back and they can put something decent on...
When the 35 still had mechanical brakes, I got the local garage [who have a brake dept], to bond some new linings onto my shoes. Same bloody stuff!! and I had no brakes!! Absolutely no braking effect, lots of pedal, but no retardation. And, it heated the drums so much that the powder coating on my wheels melted.
I ended up supplying old style woven asbestos linings and they re-did the job. [charged me again too, the mongrels!!]
Just so hard to source quality parts anymore....