Anyone have any tips for repairing buggered threads on my 1952 8N rear axles? I have been working with some light cutting oil and a 1-1/4" - 18 rethreading die and while it worked for a lot of the thread length, the hardened steel is giving me trouble in a few spots. I've run the die back and forth and just can't seem to get some areas cleaned up enough to to get the hub nuts (new ones BTW) fully threaded. Maybe a better cutting oil? Was also thinking of taking a file to them, but that seems to be the gorilla method and I'm trying to save myself the cost of replacement axles.