Vintage Single Blade CASE Pocket Knife

This is a vintage single blade CASE pocket knife in very good condition. One side of the handle has a light grayish coating that easily rubs off - I haven't tried cleaning it at all, I'll leave that to you. The blade opens smoothly and easily and locks firmly with a nice snap. The single blade is marked "XX - Razor Edge" although the double "X" is hard to see. At the base of the blade are the engraved words "Case Stainless USA", but they are a bit hard to read due to light pitting and discoloration. This knife measures about 4 inches closed and almost 7 1/2 inches open. The sharpened blade part measures about 2 7/8 inches long and the whole thing is 3/8 inch wide.