I saved as many of the clutch head and other light hardware as possible soaking for hours to days using Costco purchased lemon juice(cheapest). Maybe some light sanding to minimize the pitting look. Then a toothbrush to finish. I have lung issues, and that seemed to be the mildest de-rusting chemical I've found. The rest of the structural hardware for me was so far gone that a full stainless nut-bolt-screw kit is being used. Much cheaper and easier than single purchases. With a sandblasting on the exposed parts of stainless to make it look like old cleaned up standard hardware.
If it is NOT major structural, I'd say a de-greasing then de-rusting, as long as the nuts aren't too loose on the bolts.
