Lefty-dominant, ambi-learned because of so much stuff that just doesn't work lefty... My mom is righty-dominant ambi, my dad was full lefty, I have an aunt and an uncle on mom's side who are full lefties so it runs in the family...
I can do most things passably with either hand, can't cut a straight line using scissors or shoot a pool ball straight with either hand, I can sew or crochet with either hand, I peel carrots lefty and potatoes righty (don't ask, doesn't make sense to me either) and if I accidentally pick up a pen to write something with my right hand, it comes out mirror-image. My left hand can't figure out the mouse buttons (left-click vs right-click is apparently not intuitive when you switch, so much death in Minesweeper!) but my right hand's kind of klutzy so my preference is a right-handed fingers-trackball because my right thumb isn't smart enough to work a trackball all by itself... Could never make up my mind for high-jump, long jump or baseball which side was dominant, lefty for golf, righty for two-handed sword (because I learned a Japanese style where there allegedly ARE no lefties), lefty for sword-and-shield, ambi for one-handed sword, no shield...
At university it looked like we had slightly higher than the expected 10% southpaws in the engineering program. Either that or a bunch of us southpaws seemed to hang around in the same crew. <shrug>