This evening I'm cleaning, repairing and refurbishing a Comptometer model 3D11 from the 1950s. This was the last Comptometer the company made and has its final speed and accuracy improvements before the world moved to electronic calculators.
So I made some progress with refurbishing the Comptometer this weekend. I freed up many stuck registers, but that revealed an issue with the carry mechanism on a few digits I will have to investigate further.
@kyle impressive, so much mechanical complexity at glance, seeing that many components together is a lot more entertaining than a circuit board.