still useable?

Transmission main and counter shaft. They could be spray welded and cut back down. But you should take them with the bearings to a machine shop (or measure it yourself) to see how much interference fit you have first. The gear bearing journal with the scoring needs polished back out, and may have to be built back up. I’m sure there’s an oversize roller bearing made for something else that could take up the extra clearance, but it would probably take quite a bit of legwork to find it.