When I worked at the former RCA Laboratories as a co-op student, I hung
around a lot in their glass shop. They mostly produced vacuum tube
envolopes, but these have a great deal of similarity to light bulb
envelopes.

They used machined graphite molds for their blown envelopes, and
graphic templates to shape those turned on a glass lathe.

The tube headers and stems were purchased from an outside vendor, so I
don't know how these were made.

Harry C.