A couple of years ago I took my drives to a local shop here in the southern NH area. They specialize in media blasting and to meticulous antique blasting, so I knew they would be gentle on my drives. They use crushed glass as a media.
http://www.classiccarblasting.com/
I then primed and painted them myself, purchased new decals and they came out looking like new!
I'm sure you could find someone to repaint them if you had them blasted, this is just an idea for you.
Just realize that you have to be very careful of all the seals, and internals, you may even want to have the oil changed after you're done refinishing, just to be sure no blast media gets inside to mess things up.