You can never really tell how cleaning up will go.

I just did one razor that looked WASTED, red rust all over, but 600 sandpaper removed 99% instantly. It was all on the surface, very little pitting.

Then I had this other razor that only had one small spot near the edge. Didn't look bad at all. Took the sandpaper to it and that one spot goes almost all the way through the blade.