Thanks for the suggestion guys but I struggle with my hands a little too much to produce a neat finish which is why I'm looking to find a professional.
You can outsource to aluminum engineers. They usually do small precision work on all types of metal .
Another option is to try it yourself .
Make sure it's clear of all paint and then sand it down each time using finer grit paper.
Place the sandpaper on a block of wood and then slide the object in the same direction
Once you have worked up to very fine sand paper (1000 etc) then get a dish washing sponge (yellow with green scourer) and use that to give it a brushed finish. Will take a bit of work for steel items though.