Are you sure it rust and not moss or lichen?

Looks like a good start though. Good luck with it.

 

Yeah it's got some moss on the front but a good but of rust too

 

IMHO the best, if you have the money is to have it soda blasted or walnut shell blasted by someone who does classic cars and hotrods regularly and comes highly recommended by actual customers. First stop would be a local high end classic restoration or hotrod shop in your area for a recommendation. Failing that check with the counter guys at your largest local automotive paint and body shop supplier. Get several recommendations from different sources if you can, one or two names will likely keep popping up. It is definitely better to haul your parts 100 miles or so to someone good than let the local tombstone engraver or brick building cleaner loose on it because they are local or cheaper. A good blaster should clean the parts after and prime or rust preventive coat them for you. Freshly blasted parts will start rusting from handling or just sitting in a couple days.