WWII Bureau of Aeronautics, US Navy Plotter, Drift computer, MK IV, made by, Brooklyn metal stamping Corp, Brooklyn NY. Order No 21017 serial No 198-31. Disk is 8.5" and 10" for the attachments. Excellent condition.. The only others that I could find were in the Smithsonian..
US Navy Mk IV drift computer brass, plastic WWII rarity