When was this, and what kind of electronics were used?

I built the tow reels guessing 5 years ago. I designed the electronics, a very simple circuit.

A single pole double throw power relay to drive the motor when energized, the NC (de-energised) contact put the motor braking resistor across the motor. The power relay was driven by an ELK924 sensitive relay. The input current required for the relay is low enough so that a simple RC time constant circuit, triggered and kept charged by a Hall effect sensor with 4 magnets embedded in the aluminum side of the drum, would keep things energised until rope reeled in. Push button to start, hall effect takes over until end of rope, RC circuit drops out and motor stops.

The sensitive relay was wired using both sides of the relay, one to drive the power relay, and the other to act as a anti-bounce back circuit. The reel slowing would drop the sensitive relay, but if the reel bounced back to align a magnet with the hall effect sensor, motor prevented from being energised again until the retract button again pushed.

All the documentation went to SoaringNV. I may have a schematic with the circuitry somewhere, though not on this computer, sorry.

bumper