Why am I doing this by hand? Because it’s too small to fit into my sewing machine. This is also why I had to finish the seam allowance by hand.
She looks like someone’s holding a gun on her, doesn’t she? The arms set at that angle because of the angled arm slits on the body. This places a disproportionate amount of fabric under the arm. That’s why I say this sleeve is basically self-gusseting. The extra fabric a gusset would add is there because of the angle the sleeve is set at. Pretty slick, if you think about it…. (Not too flattering to wear, mind you. Gussets put the extra fabric directly below the armscye, so there’s less bulk at the front and back shoulder area.)