I will hazard a guess. It is referred to as a "officers" compass due to who they were issued to. I see where one similar sold recently for 113.50 on the bay but yours is in much nicer condition and you have the case and lanyard where his did not. I would guess 250-300 value wise on yours based on my observations. I read they have a pretty large following and I would not be surprised, due to the nice condition and completeness of yours that someone might pay more. Im no expert on Britishicon field gear mind you.