I have a Pride Pursuit XL scooter that I want to reverse the action of the *wigwag* throttle,
so that pulling BACK on the left side will make it go forward and back on the right side
will make it go in reverse.
On my scooter, the control is just like an ordinary pot, spring loaded to the centre position. Measuring the resistance between the wiper and either end (it is symmetrical) the resistance varies between 450Ω and 5kΩ, and 2.6kΩ at the neutral position. Therefore, on my scooter, swapping the end wires on the pot would do what you want.
I can not tell whether your scooter is the same. Here is a picture inside the control box:
Just to be clear, on mine there are just three wires to the control - the red and black in the picture feed a buzzer.
If yours has five wires then you will need to measure the resistances between the wires and see what it does.