The alpha numeric “6A” is the RAF Stores “Section” of the Vocabulary of RAF Equipment and 726 is its individual reference number in that catalogue. As I understand it 6A/726 was the reference number allocated to the Pilots Type Magnetic Compass Type P8.
And yes I would think it would have value to a collector, though if you like you could give it to me!

Thanks for that, so it could have come from any aircraft using the P8 compass. Difficult to trace a particular type I would imagine. I would love to give it away, but I am pretty strapped for cash at the moment, so if I can get a bit of cash for it and have it go somewhere where it is wanted, I will be more than happy.

I don’t have a clue what to expect for it though, there must be hundreds of them in circulation and probably in far better condition!