GE Saf-T-Gard 85W Halogen PAR38 with integral photocell

Having seen one of these on another site, I had to see if I could find one, fortunately a seller on US eBay had one left. The shipping and customs charges cost more than the lamp, but I think it was worth it, I have never come across one of these before. The photocell clipped to the side of the reflector seems to work quite well, although I'm not sure how well it would perform in a real-world situation.

Unfortunately the etch is difficult to read, but I did see faintly the numbers 90/2 although this hasn't come out in the picture. Can I assume February 1990..?