With a buffing wheel, it shouldn't take long. Once polished, I would apply wax to it rather than a clearcoat. Any coating (i.e., paint) should not be applied to a polished surface, it should only be applied to a slightly courser surface so it has something to grab onto.

I have an old steel crankset that the chrome is peeling from. I plan on removing what's left of the chrome, polishing it and then applying wax. This will require some maintanance, but this bike won't be used as a daily commuter.