Try these guys for parts:
Ray's Mower Shop
112 Terrace Rd
Boyertown PA. 19512
Hours 9-6 weekdays 9-5 wed. 9-12 sat. Est time
Noah Souders (owner)
They were Bolens dealers for many years and they sell used and new parts by mail for Bolens tractors.
I have dealt with them, and I feel comfortable recommending them.