Roger, as a last resort in case no one on the list has experience with this you might call Ron Rachubka at Syracuse Industrial Sales in Syracuse, NY. The phone number is (315) 478-5751 between Tuesday- Friday, 7:30 a.m. - 5 p.m. Eastern time.
Ron sold and repaired new and vintage P-C machines for over 30 years. If a woman answers, that is probably his wife. She knows a lot about the business, including about parts, but I don't know whether she would know the answer to your question.
Let us know how you make out with this repair. I'm sure one of us may likely need to do this some time.