For your consideration, here is a Cable Out Gauge, made by General Electric, Part Number 8DJ48 GBY, Sub 1. It measures up to 3,400 feet. I think it is for an aircraft, but I am not sure. It looks like a plane cockpit gauge.

It has three leads in the back of it. The housing measures 2 5/16 inches square. I don't know if it works. It has some wear on it. Item pictured is the actual item up for sale and comes from a non-smoking household. (229.840g-.13bb)