[horsa]

Since yours was running with no issues from the differential, I'd say flush it out on the inside and repaint it on the outside. I had to tear mine down because it was a complete unknown. It was supposed to be NOS but having been stored by other people outside in the rain and mud for untold years, it was completely rusted over. I had no way to know if it was usable or not. And even if it were NOS, it could have still been rusted on the inside as well due to poor storage.

We're stuck with cold and damp conditions here at the moment as well. I have parts from two other smaller projects that are stripped and waiting to be painted. I'm priming some items when I can, one at a time on pieces of wire but its been slow. Spray outside under a covered porch and then carry them throught the house so I can hand them to very slowly dry in the garage which has really high humidity. Really my only option if I don't want them to start rusting again.