Catalina Direct has good pintles and gudgeons that are designed for the Catalina 25 and that would likely work for you. They are a lot stronger than the original:
Catalina Direct: Pintle Short 1/2" for Standard Rudder
Catalina Direct: Gudgeon 1/2" Retrofit Three Bolt Hole C-22, C-22 Sport, C-25,CP-22, C-250
They fit both their 1.5" and 2" wide rudders, so they should work for a 1.75" wide rudder too.
I can't compare them to the Sea Sure fittings, but the pin size is 80-100% larger, which isn't nothing. The original ones on these boats weren't very good, but the replacement design is a lot more robust.