Michael, indeed it is a PH302 and looks like I'm going to need to improvise at some point soon.

Donald, there is a diffusion panel with the enlarger, as well as a second panel the owner said he used as it "worked better that way." The writing on this bulb is indeed around the base and not at the end as would be normal with a household type. If I can't find one, I'll look into your suggestion for a decent replacement. I'm sure "Quido" can think up a working solution.

Alex, I'll give B&H a try and see what they have in stock.

mrcallow, the link posted by michael looks to be an exact match. Have any like this one?

Thanks to all. tim