I really don't see any justification in blasting your frame unless you strip it down to just the frame and build up from there. You really can't leave any moving parts on it because the sand is just going to get in it and ruin it anyway.
Just tell him that you have a bare frame from a '53 chevy half-ton pickup and how much would he charge to blast it down to bare steel.
If you have a real cherry specimen to start with you might as well do it right. If you just want to get it nice and shiny and drive it you can save a lot of money and time by scraping, wire brushing and giving it a couple good coats of (oh my god, he's going to say it again)
ENAMEL.
