Hi guys, Now I'm sure this use to belong to the RAF and probably many moons ago too but knowing most of you guys who work in aviation have an interest in it outside of work I thought I'd try here before nipping over to e-goat. This was given to me a few years ago and I was told it came out of a Spitfire but I'm not so sure, the back I think is made from Bakelite although it is black and Bakelite was usually brown. Written on the bottom is the following. Navigational Computer MK3D. REF. No. 6B/180 And thats all I have. Sorry I did try to add a pic but its not having it.