I took your advice and scrapped the rust off with a brush, steel wool and sand paper to get to as smooth as possible, then took a can of silver spray paint
that I already had and gave it two coats. Looks pretty good and ready to reinstall. After talking to a metal fabricator, and thinking about how expensive it might be to fabricate this part exactly, I took the much cheaper route. Thanks for your assistance!
Now, if only I could get the door to realign correctly. Looks like the lower bolt needs to be shimmed to lift it properly to widen the gap on the right. Suggestions?