I've located the controller.
Brushless dc36v
Model: kt36zws-xfklcdsm
Min Volt: 31 +/-0.5v
Max current: 14 +/-1a
Speed set: 1-4.2v
Brake input: low level
It's got the following block connectors:
Lcd display
2x brake
Speedo
Throttle
5 wire block with thin blue, green, yellow, black, red (goes to...