Gremlin:
My bulb looks just like the one in the photo you posted. (Ha! Bet most of you folks never saw a headlight bulb that looks like that before?
They were called "Pre Focused" because just plugging them in automatically located the bulb in the right place and they were quite popular back in the 1940's for headlights that didn't use the "new" sealed beam type.
Prior to bulbs of this style a mechanic had to adjust the fore/aft location of the bulbs to get the lens to shine the light in the right direction.
I used to have a 1939 Motor's Manual that described how to do this on your Graham, Pierce Arrow or LaSalle.
The large sheet metal flange on this "Pre-Focused" bulb positions and times the light.)
The bulb I installed is a 40/50 watt bulb.
THAT should dazzle the kiddies.
CMW as usual, already packed and shipped my order so I should be getting it in a day or so.