Matt
I've had trucks grit blasted, sand blasted, slag blasted, spent hours using chemical strippers and a scrapper, wire brushes on drills and angle grinders, I've even burnt the $$££### stuff off.
All these methods work and they all have a place in restoration.
Like Gordon says with blast cleaning it depends what material you are trying to clean with regard to what you hit it with. In my opinion blast cleaning if it is done properly is effective particularly in semi closed sections.
Remember however that you are eroding the surface and therefore an immediate application of a good two-pack primer is advisable in our damp northern climes here in the UK.
Standard red oxide will become porous with time particularly if a flat topcoat is applied over the primer and you will end up with the dreaded brown spot, I speak from experience here with a jeep tub a few years ago.
Get a professional to do the job, preferably someone who specialises in vintage motors, not just an odd job with a compressor and a blast pot, this is a recipe for disaster especial on relatively thin cab sheet work like you have. The best blast operators have heated indoor blast booths, expensive but worth it in the long run.
One last point for posterity, be prepared for an unpleasant surprise or two in the form of metal moth showing up as a result of blasting, I was doing a jeep for a guy who was nearly in tears after his good body tub came back from the blasters looking like a lace curtain after all the filler and grot had been blown out of it.
Good luck and choose wisely
Pete
