Hi there try and find sombody that does soda blasting that is very gentle then get it polished and it will look fantastic. I have an aluminum world war one model plane that my great grandfather made and it languished in our shed for years I had that soda blasted then spent an evening polishing it and it looks really good I then laquered it with some auto body laquer to keep the shine. Its still as good now as it was 10 years ago when i did it.:D