I think it's MGA that's starts the ICE, as @donald once commented. It would not dare to fail to start with a 55kW motor driving it!
Note the starter is only slightly less powerful than the ICE.
This is also I understand why the top speed is 100, as over that the speed of MGA is too fast to clutch to the ICE.
Hope I got that right, MGA is the 55kW Motor/Generator and MGB is the 149kW main Motor/Generator.
Looks like a breakers to me. I bought one such 3yrs ago from a write-off Amp which had crunched the front left into a stone wall. I chose the back right wheel. I wouldn't have wanted the front left one unless it had been safety x-rayed. Caveat emptor.