I have removed my Islander 28 (built in 1978) mast for repainting and replacement of bulbs. The bulb which shines downward onto the deck is unusual. It is a silvered reflector bulb, ca. 2" in diameter, with a double contact bayonet base. The only markings on this bulb are: T3600. The face of this bulb is flattened and made of fairly heavy glass. It looks very much like a bulb from a slide projector with a heavy glass front and bayonet base. I need to know more about this bulb so I can find a replacement. Any ideas or suggestions to help me find ths bulb would be appreciated.