Compass, Telltale Mirrored Magnetic RCAF Type P-7 1938 (COMP24)
This RCAF telltale compass, intended to be installed upside-down in an aircraft, is pre-WWII.
According to collector George Fulford's notes:
Now, this one compass I want to crow about! I have been looking for this for decades – and so were a number of competitive bidders, so it did not come cheap. This is the only true upside down flight compass ever made. You don’t read it from the top but via a mirror below that shows you the compass face, as clearly as from the top, however if you try to visually bypass the mirror everything will look wrong.
The base stand is marked RCAF and the fact that it came from British Columbia makes me suspect that it was flown in a bi-wing twin engine Supermarine Stranraer seaplane built in Canada but designed by Mitchell who also designed during the same time the glorious Spitfire. I only make that statement because no one in their right minds would associate the same designer to both aircraft. The Stranraer was one ugly aircraft and I had a chance to poke around in one in Vancouver and I wondered how on earth the string bag, with apologies to the Fairey Swordfish, could get airborne. The RCAF got rid of them at the end of the war and bush airlines bought them up, and the last one was still operational in 1971!