Refinishing exterior door handle advice. Pic inside

Hey fellow homeowners, will be repainting an exterior metal door at my house in the next couple of days and my door handle is in pretty sad shape (see pic).

I believe that it's made out of nickel or aluminum. Unsure but can I just use some mother's aluminum polish to clean it up a little or how can I restore it's look ? Its original from 10-15yrs ago probably and works fine just doesn't survive the look category department

Thanks for any advice.