Thanks Barry. Heat will be my next attempt. Though I'm a bit worried the silly thing has a hidden trick; because I tried liquid wrench and a pulley puller and only succeeded in popping the bolt heads securing the pulley puller to the pulley. Most satisfying pop, but didn't seem to budge the pulley an iota.
There is nothing as obvious as a nut or bolt, just an 1/8 inch hole in the center of the shaft. Have you hear of such a locking mechanism?
Out of curiosity, if there was a nut or bolt would it be threaded counter to rotation?