So, Fed Ex did persevere enough to come back with my package on Saturday and here's what happened.
I tried on the smallest size and Mr. April felt it was a slam dunk. Yay. Next day, tried it on again while wearing the bra I would actually wear beneath it and then it had a huge button-gape across the bust. The next biggest size would be too big, so back both sizes go.
Day after that I ordered this one that Angie recommended: https://www.google.com/search?.....D-Q:162248