There's a substance that Loctite makes for refurbishing seal grooves on power plant turbine shafts. Evidently you apply it on a lathe with a squeegee, then after it hardens, turn it down to size. If it'll work there, it'll probably work on the first motion shaft. Google to find this. I don't have any other info.
I was originally interested in it as a solution for worn-seal grooves in our steering shafts.