I like Mother's Mag and Aluminum polish. Polishes every kind of metal I've used it on.
... I still have small scratches left over from removing the paint, but the shine is there.
Thanks for all your suggestions! My local hardware store was out of Mother's, so I bought some Blue Magic metal polish instead. I was quite impressed with the results. I still have small scratches left over from removing the paint, but the shine is there.