Yesterday I spent a few hours restoring this Monroe Model G calculator. It was only after putting everything back together that I discovered the accumulator is only underflowing half the digits when doing subtraction/division, so I get to take it apart again today and fix that.
@kyle Beautiful machine!
This is the carry mechanism for the Monroe. The bars form a wave and the last few move, but were completely seized up. A few hours with some oil, pliers, a screwdriver, and ultimately a heat gun, and it finally loosened up. Subtraction finally underflows all the way to the left!