I have had similar issues. My Tormentor breaks EVERY time I transport it, making me wish I had pinned its blades. As for the Executor... It gets its own bubble wrapped box and still I bring glue with me just in case.
The only thing I can think of is a custom made case with magnets on the base, plus holes in the bottom to dislodge the model when the time comes to field it. That may take as much time as the model itself though.
In any case, nice job.
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author of Syncing Forward and other stories...It's a dog-eat-dog world, and I've got my Milkbone underwear on.