I have acquired an old series incandescent luminaire that I cannot
identify. I was hoping someone might recognize this lamp and be able to
identify make, form # and approximate vintage.
It is a high voltage series street light. I doesn't have a film cutout disc but rather a film cutout socket insert. It uses a two piece Holophane refractor where one piece fits inside the other. The outer refractor has vertical ribs and the inner refractor has horizontal ribs. Together the two refractors diffuse the light pretty evenly.
The socket rides on two threaded conductors that extend down from the supply conductor lugs. The socket can be adjusted up or down inside the lamp by rotating these threaded conductors.
The reflector appears to be cast iron.
Here are photos of the lamp disassembled.