For my 1991 K75RT, I used a "Wilson" Electrical products (part # 62-15-6635) and total cost was $16.45, a pretty inexpensive repair (regulator and brush assembly), which I bought at a local auto parts store here in Red Deer. I think it was for a 1960's era Volvo with a Bosch alternator, but could be a bit off. Anyway, since you are in the USA, it will likely be less expensive and probably easier to source... Hope you have some success!...