As I said, the soda blasting was done by a professional aircraft painter, who does corporate air craft as a profession. Since he was one of the few people I could find at the time that did soda blasting regularly, and figuring he know how to avoid distortion on large soft panels, I believe he was a good choice. I did have concerns about cleanup, and we discussed it. I told him to prep and primer so as to make sure it was done properly, aqs if it was his own restoration.
As an aside, He chose to use a mixture of soda and garnet on the rusty areas. He claimed garnet was better than sand or glass on steel, to avoid painting problems.
As to my little current project, I will take the advice for multiple washes, etc before the primer coat.