Awesome response. thank you.
When I collected the robot and controller I rooted around and found a controller in a box. Together with a spare set of controller cables. From a 2017 order for the similar robot for one of their customers . So it is not the original one, but for the same robot, but unknown controller version. and not the model referred to in your post.
It is 50817-0066.
The plug is compatible.
Based on your email, I do t think there is a risk to plugging it in and seeing if it works?
Thanks