This is not my lamp. I came across the pictures here Searchlight Projector - Victorian Collections I have seen a few SL1's but this is the only one I have seen like this. It would need to have slots in the underneath of the box on the case so they could be loosened, case moved and then bolts tightened up. I'm not sure that the box is even long enough to accommodate the slots in the case. Could those be for something else perhaps ??
Very curious, indeed, @Anthony. It looks like a trip to Warrnambool is in order for a closer inspection. Cheers Tony
The pump cap (set up for use with an external pump) appears to be the standard FL pump size, rather than the small bore pump on the 1937 FL6 tank. I’m still pondering this beast... Tony
I’m tending to the hypothesis that it could be a Tilley SL3 light box with the three burners removed (hence the slots in the side of the light box), and an SL1 burner fitted (hence the need to cut two holes (one hole in front of one slot, one hole behind the other slot). Note: I have only seen these pictures of this light, and other photos of SL3s here on CPL, and photos sent to me by @Anthony. Tony
@Tony Press , the hypothesis sounds good to me. The round hole for the single air tube would have been needed to hold the tube from banging around and damaging the mantle. @BigStevie , of course I agree. Equal or not.