I’d agree. How is it wired?

Bloody hell, what a find! Looks like an Osram GEC 250W MA lamp. Pretty unused too!

Interesting. I'd guess the tungsten was to add a bit of colour to the otherwise grim MA!

Incredible it’s still got the original lamps in!

Certainly could be original lamps. It's a 300W tungsten, I can't find an etch on the MA lamps.

I agree with FrontSideBus's statement. The tungstenamp is NOT the ballast for the MA lamp; rather, it serves to enhance the color. It's a kind of mixed light. The ballast for the MA lamp was most likely mounted externally in a gearbox. Such designs were also common in continental Europe.

Oh wow! thats a very cool find! as Olav mentions these where common in Europe and to a much lesser degree in the UK when mercury was first introduced, the GLS lamp is not a ballast, but simply there to provide a bit of extra red light! very cool to see one over here, while they did exist here they where not so common, similar-ish setups also existed in the US, but I think often they would just use a mix of mercury and GLS fixtures

Amazing!

Knowing about these 2 lamp fixtures (medium pressure MV lamp and a GLS incandescent lamp) this was basically a colour enhancement technique until coated medium pressure MV lamps like @Andy has got became more widespread or more commnly the high pressure coated mercury lamp - I didn't hear about them being self ballasted so would need a ballast - though considering what Danny said, worth checking the wiring especially due to it being pre 1960s

I've just checked the wiring, it is two separate circuits, you are all correct. The tungsten is to improve colour not a ballast.

Is there any marking (or signs of it existing once) which socket is for which lamp ? Screwing the MA into the socket for the GLS would be exciting for anyone on the factory floor

I don't believe there is, but the likelihood of both lamps failing at the same time would have been slim, if they were ever changed at all

Most likely that the incandescent would have failed first and the fixture might have seen at least one change due to the fact of how the lamps were built to last

One of the tungsten lamps is pearl, while the other two are clear, so you could be right there

I've just tested both MA/V lamps, and both strike and run up well. It's been decades since they were last ran and yet no problems coming back to life!