I'm no expert on b& w roller processors, but do run a cp-31 for ra-4. Check if there are tensioning springs or bands that keep the rollers squeezed together. Are they all there, and still keeping the tension?
I suspect that some sort of ferric corrosion may be from a rusting shaft of a roller might be contaminating things on you. Anny ferric residue migrating to the edge of the rollers, and then that might be the culprit.
Wind up the scientific experimenter in you.
I would feed it pre -fixed (from a tray fixed and washed) batchs of 1" x8" strips.
Feed these strips in with only water in the developer tank, and the fixer tank dry.
See if it is coming out dry when on one side, and then on the other damp. That would show poor roller tension uniformity.
Go from there one step at a time, with the cover off, while working with water passes to see what else turns up.
If you find a dirty machine in need of cleaning, and the roller are not foam, I would consider letting it stew on a bath of dilute toilet bowl cleaner
Combined with wiping with nylon dish scouring pads and paper towels,. almost any roller processor should come clean.
Clean any transfer racks as well. They can sometimes be the culprit.