Scary as this sounds, I drown them in brake cleaner, then do the same with WD 40, then use very low pressure air to sort of flush out the WD. Then clean/dry the points and give it a try. I am maybe 2 out of 3 batting average on this working. I figure if it isn't working to start with, I can't hurt it much.
Now, I'm sure someone will explain how WD isn't a lubricant and I understand that, but this has worked for me. Maybe when you get it running again you could put some very light oil on the moving parts.