I think I got the thing fixed well enough to use! I tried some wooden wedges first, and they didn't do much more than get stuck. I think they may have spread out the "good"/drive side just a tad, because I was finally able to get that one to thread in cleanly. I did this with the old Tange BB shell, stuck the axle in and used the hole in the shell as a brace, and hammered the axle into the bad side where it's pressed in. It pushed it back out just enough to let the non-drive side thread in relatively cleanly.
Not sure if I want to take it back for another clearcoat after the decals go on - at least not without a BB threaded in! Thanks for all of the help, guys.