Have you thought about rolling in a new bearing and see how much clearance you have.
I'm going to guess, and say the ruff texture on the crank is no the crank........but bearing material stuck to it.
You may need to remove the crank to clean it off.
Steel crankshaft is way, way stronger then a bearing.
If it was mine i would take it to a crank shop to have the journals polished(including the thrust) throw a set of bearing at it and call it a day.
