I recently purchased this airspeed/altitude indicator at a local auction because I thought it looked interesting. It is made out of plywood and looks to be a mock up. There is a metal tag on it that says: Machine Gun Trainer Mark 2, The Vitarama Corp. Long Island City, NY. 1942. After some internet searches I found this link (The Waller Flexible Gunnery Trainer). describing the Waller Flexible Gunnery Trainer "one of the top secret developments of the war and was on the restricted list of equipment". "The Trainer was used by the U. S. Army Air Corps, U. S. Navy. and the British for the final training and retraining of machine gunners. Just wondering if anyone has come across any parts of this trainer.