RAF Regiment perhaps, a la Capt. C. Shore?
Peacetime military amusements: "if in doubt paint it"?
Speaking of these telescopes, I picked up a few NOS lenses from an estate full of surplus oddments recently. There are two lenses 2.682"/68.3mm dia. that are a close fit to each other on one surface. With my Geneva Lens Measure from the same estate, they measure +0.5 & -2.33(approx) and +2.0 & +0.75. Assembled thickness of the doublet is 0.52"
I suppose these could be from a TSR/Sig/GS type or even a REL Telescope, Observing, Snipers, but I don't feel like taking mine apart to find out!
There's a cemented doublet as well, 1.214"/30.86mm dia., 0.553"/14.07mm thick, +6.0 on one side and +2.5 on the other.