Help please to identify RAF Canteen's cup?

Hi all;

Well, it’s aviation related and historic I guess, so…

I’ve had this cup / beaker for about twenty years and have no idea of it’s age etc. I’m familiar with the white RAF marked ceramic crockery, but I haven’t been able to find out anything about this cup.

Does anyone have any idea as to what era this would be from? Is it pre-war, wartime or post war? I’d love to know. It’s earthenware and in super condition, but I don’t use it as it sits with all my other clutter collecting dust! If anyone can help, I would be most grateful.

Thanks in advance!

Best regards;
Steve