i feel like i've seen a fair number of male-bodied gq folk at genderqueer, and a good rl friend of mine is. if you want hand-wavy numbers, you could probably ask there.

fwiw, i think you're right about the motivations for some females to id as 'something else', though probably not for all, or even most; i'm not uncomfortable in my female body, but being expected to act like a woman, whatever that means, is just ridiculous. besides, apparently real women have curves.