The derivation is probably from a watch stem, which (in the days before electric and motion-wound watches... remember those?) was used to wind the watch mainspring.
I've also heard "stem winder" being used a a derogatory term for someone who likes to stir up trouble. We've got a bunch of 'em around here.... Joe Ellis ? CEO Bethlehem-Ares Railroad ___a________n_mmm___mmm_mmm_mmm___mmm_mmm_mmm___mmm_n______ ___|8 8B| ___ /::::: / /::::X/ /:::::/ /:::::/|| ||__BARR| | | /::::::/ /:::::X /:::::/ /:::::/ ||
---------------------------------------------------------------- [(=)=(=)=(=)=(=)] |_________________________| [(=)=(=)=(=)=(=)] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Serving America's Heartland Since 1825