For all the needed work, lately I've just been using brand new cabs with MDF faced plywood.
Because they are already primed, and have no knots, holes, checking or boatmen to sand and fill, a new cab is the way to go.
A cab with decals (unless it is a cab that came from the factory with decals) is not original anyway, so better to get a perfectly smooth, no stink, no mildew, brand new cab.