I have just built a left hand accelerator for the wife as she has a paralyzed right leg.
while i was at it i realized that i could make the action logarithmic instead of lineal.
as i was using a cable from a bicycle brake system i realized that the first movement of the pedal could be a slow movement of the accelerator cable but as soon as the pedal movement goes past a certain point the linkage to the accelerator is moved faster.
i did this by using several studs on the moving plate attached to the foot pedal
these had different spacings from the hinge point
this means that during slow maneuvering the accelerator is moved a small amount for a larger amount of pedal movement during slow maneuvering
thus the car has better control and for acceleration to get away fast the pedal has to be moved only a little bit more when the studs spaced further away from the hinge wrap onto the cable thus giving fast accelerator movement for small pedal movement.]

a cable from an old accelerator is fed from the pedal over to the top of the right hand accelerator pedal
and the wire is clipped onto where the other cable to the motor is situated.
a suitable attach ment under the dash holds the cable sheath
i found a bolt holding the fuse assembly was ok.
for a warrant i have to remove it as it is not 'officially' certified (cost $250 )
it is only 2 minutes to remove the clip and pedal
It was attached to the rubber mat and can be shifted a little each way to suit the driver
conventional right hand accelerators could also be made to do the same but i could see Resistance from manufacturers