The knife has blades with wear from a poor sharpening method. The main blade has softer snap compared to the other two. When looking up Imperial tang stamps this one seems to be in the 1946-1956 era of production.The clip blade has " STAINLESS " then " IMPERIAL " with " PROV. U.S.A. " below. The Spey blade has " STAINLESS " and the pen blade has " U.S. Foreign PAT. PEND. " both on the pile side. It is difficult to see, but the clip blade is has on the face " Razor Blade Stainless " in and arch over a image of a razor  with " SUPER Made in U.S.A. " before it. It is 3 5/16 inches long when closed.