The guy that "restored my 951 summer of 2013 said he changed the tranny fluid. Just for yucks I changed it the other day (after <1k miles) and it came out pretty dark especially when compared to the new gear oil I put in.

This has me questioning what else should have been done that wasn't.
Given that this car is an '86 with 175k miles on it and I only have records back to 2007, I'm wondering if there's a complete maintenance guide online for the 951.

For example:

Yearly do:
- change fluid A
- clean part B
- check part C

At X miles do:
- change part A
- adjust belt B
- change fluid C