I think you right Tom. I have or had, i have not seen it for a while đ a similar one that was for a watchmans clock. The number is reversed because it presses through an inked ribbon onto a paper disk in the clock.
My one has a ratchet on the bit so once inserted in the clock it cannot be turned back. made of brass and it was on a length of chain in a little box that screwed to the wall.
