All it would have taken is one guy with a bit of ingenuity seeing a refractor sight mounted on a naval gun and coming up with the idea of finding a spare to attach to his rifle. No way to prove it never happened and since it’s plausible, I give it a pass.

It’s a reflector sight, in use since the early 1900s. Just cause you didn’t see it in old Cod or Saving Private Ryan or Band of Brothers doesn’t mean it didn’t exist.