Here's a project recovered from the basement of my grandparents' house a few years back, a Flyer 3326 that belonged to my uncle:
This is why toy trains should never be stored in a musty damp basement. This is in very rough shape, with flaking paint and quite a bit of corrosion on some of the plated parts. The real problem is the wheelsets are all swollen and crumbling, as are the gears. An effort to disassemble the motor may see it fall to pieces in my hands.
I was going to gut it for parts and pitch the rest, but, given the family history, I don't think I could stomach doing that. Instead, I think a bottoms up rebuild will be attempted. A York friend sells reconditioned motors, so I may see if he has this one...that would be far easier (and likely less expensive) than trying to re-wheel it and recondition it myself. The boiler casting and trim seems in decent enough shape, and the drive rods and eccentric gear may polish up satisfactorily. The pilot and pony trucks will likely be problematic.
I don't know. It's going into the project pile along with the rest of the set. Stay tuned...