Help: Feed Screw with a spot with built up rust

[EdisonPhonographGuy]

I submerged it in wd-40 for 2 days and used a very fine brass wire brush. I then took the feed nut and used it as a thread chaser. It would be alot cheaper to replace that than the feed screw if it boogered it up. It didn't and I chased it, soaked it some more, chased it until everything was smooth. I looked at it through a loupe and some of the threads corroded a little, but not enough to stop it from keeping on track.