Just a difference between American and European tripod screw standards. The Europeans settled on a 3/8" screw.
Your camera probably also came with a lens marked in meters, and does not the word "Germany" engraved on it. (Well, if it was sold to England, it would be feet.) It was just the US that required the marking of country of origin in English. (If Leitz had wanted to mark the country of origin for their own purposes, they would have marked it Deutschland.)