1962 Hi-Standard Models A,B,D,E & C Instructions,8-1/2" 11" closed and opens to 16-1/2" x 11".One-Half of each side when unfolded to open is shown.It is maeked " Parts List No. 993-82 Revised 6-62".My take is that Hi-Standard printed these in 1962 for gunsmiths and punched the holes for a binder. Excellent Condition