My somewhat educated guess is that this is neither a "service station" nor a tire factory. It is probably a retread facility. Retreading was very commonly done on passenger car tires for many years; I believe it is still commonly done on airliner, off-road industrial, and large truck tires because the carcasses of those tires are expensive. Large airplane tires are retreaded many times because of their expense and short tread life. (disclaimer: my knowledge of this topic is from 45 years ago, so maybe wrong today).

[As noted in the caption, we are looking at this place -- the Gurley-Lord garage at 1517 Mission Street. A business where service is performed is a service station. - Dave]

When I was very young a good friend of my father's owned a recapping shop in my hometown. The hot rubber smell from the steam-heated molds is the most distinctive memory. The men buffing the old tread off the tires to be capped left piles of rubber dust, so the place I remember wasn't this clean. The man on the left is inspecting the inside of the tire for a stone bruise or a puncture that could leave a rough spot that would need to be cleaned up and patched. Some of the equipment to repair or inspect tires looks like it came right out of Torquemada's toolbox.

I watched the jazzy video and was exhausted in that short time! All I could think was how tiring (no pun intended) those workers would be after eight hours of handling those tires!

These molds would have been used to shape the tires, either to build them up from scratch or perhaps to patch them since this was a service station. The molds would likely have gone into an oven after the rubber and any strengthening elements (e.g., cables or wire mesh) were laid down, tacked together and formed by stretching and spinning the rubber into its final shape.

[The molds themselves are the "ovens." The white covering is asbestos. - Dave]

This video from 1934 shows the whole process at a tire factory:
https://www.youtube.com/watch?v=zXjhV2LEpPo

This video may be from the 1920s and is clearer and much shorter. If you like hot jazz, it's the one to watch. https://www.youtube.com/watch?v=_NgH_8chCog