You will also want to keep the capstan clean. This is the small rotating shaft that the pinch rollers bear against. It should look nice and shiny- any texture means its dirty.
Dirty pinch rollers can be caused by tape shedding and the rubber of the roller perishing. The deck is old enough that you might consider having the pinch rollers replaced.
As far as the cassettes shedding oxide- put them in a warm car for a day- that will allow them to get rid of some of the moisture they have picked up from humidity over the years. Then they will shed less.
Dirty pinch rollers can be caused by tape shedding and the rubber of the roller perishing. The deck is old enough that you might consider having the pinch rollers replaced.
As far as the cassettes shedding oxide- put them in a warm car for a day- that will allow them to get rid of some of the moisture they have picked up from humidity over the years. Then they will shed less.