This is an insulator I recently came across. I thinks that the stamp should read: LOCKE HI-TOP 77V USA The stamping is pretty deep and full of glaze, but it looks like the "L" has been replaced with a "C" and the "HI" is actually a "ML". The "V" also seems to be missing. I looks as if the stamp reads: COCKE ML-TOP 77 USA I was wondering if anyone could shed some light on my confusion.