In keeping with my theme of being wrong about everything, those may not be too bad. Those are sealed pots...which might actually keep the dirt out and the lube in.
LOL! Yes they are sealed, but I still ended up replacing the 250k one in my S-500 in less than a year of owning it. It was noisy, and IIRC, there was no way to clean the wiper with contact cleaner.

I still have it (for some reason???), maybe I'll take another look at it and see what's what.