I wouldn't recommend drilling a hole and adding a little oil. I'm making an assumption this is a three speed, but if it's a two speed, here's the bench test procedures on those as well.
If, by some chance, the armature is not exactly "plumb" , on a three speed a good way to realign the armature is to give it a decent whack with a rubber mallet on the cylinder screw. Don't hit it too close to the brush cap, that can break your brushes.
If you want to give me a call, feel free, we can explore some possibilities and see if we can get it working again. When you say you cleaned it up, how do you mean you cleaned it up?
