I was looking for a headlight bulb for my 1993 Massey Ferguson 240 and was able to find them locally at a auto parts store, they are the same bulbs used on snow mobiles.

So I figured I would post the part numbers for others that may be searching as well.

Bulb BT Type P45T 12v 45/45W
Part# 9589 CTC#26-2054

Buy Ignition Products Snowmobile/ATV Bulb P45T 45/45W 9589 at Advance Auto Parts