Did you have the keyway pointing up when removing the pulley ? I find it strange that it's missing, unless someone has been there before. I would pull the seal and check it hasn't been pushed out of the keyway, back towards the timing gear. as far as getting a new one, I would think a Benz dealer would be your best bet, unless you can find someone splitting a motor. Have you e-mailed Rob at needswings , or Mr Mopar to see if they can help ? Sorry I can't be of any more help........