Bill,
If you are interested in an original-style drain cock that matches some I have found on old radiators and engines, Eaton (Weatherhead-Eaton) sells one, catalog number 6788 (1/4" male pipe thread). This one has a "snout" that allow a piece of tubing to be attached (makes for cleaner draining directly into a pail/container).
Tim
NAPA:
WH 6788 Dorman sells a similar fitting: 480-245
