I got some good feedback from people over the last several days about my plan to get the car blasted with transmission in place. Short summary: "don't do it." Even with careful taping and masking of the bell housing/axle boot areas, there is too much potential for gritting things up leading to a costly rebuild shortly after reassembly.
What does this mean? Well one, I won't be getting to the blaster quite as soon as I had hoped, but I still am aiming at getting the car there before the end of March. Second, it means I have to build at least a partial dolly for the car, as without the transmission, there are no rear wheels, and thus no way to move the car There are simple plans on 356registry.org for building one that attaches to the transmission hoop and uses a single large caster to provide movement and balance. With the engine out, this should be sufficient for movement around the driveway and onto a flatbed truck. Plus, this gives me another opportunity to practice my welding skills on something that doesn't have to look pretty, it just has to be strong!