I got e-mail from my cousin Lana RE: armhole shaping, which I reproduce here.

"About underarms-- I always go ahead and bind them off as in the pattern, but graft the short bits on the sides to the short bits on the sleeves with the castoffs turned to the inside. Oh, and I do the grafting a half stitch off, if that makes any sense, so the stitches meet like so:

vvvvvv
^^^^^^ (ed. note -- this illustration didn't turn out quite right.)

with the result that from the outside, the underarms look like a three-needle bindoff. I used to graft the castoff bits together in the usual way, but the half-stitch mismatch at the side seam always annoyed me."

Thanks, Lana!