thx for posting the thread I also have the same problem
is there any repair shops in North America?
There are lots of repair shops that specialize in older outboards. The best one in Maryland used to be located on Ritchie Highway, but I haven't been down that highway for years, so I'm not sure if they are still in business.
The other one I knew of was previously known as Imperial Marine on U.S. Route 40 in White Marsh, MD. They had an incredible service department until a few years ago, and they had a service manager who really knows older outboards. When they sold out to Marine Max he retired, but they may still work on these older engines.