My thought is that since this is a Leica, the components would be of very high quality. The only transistor(s) needed would be in the exposure circuit. In my Super8 Bolex the meter circuit is powered by mercury batteries, while the motor circuit is powered by 4 AA batteries. Your camera might have the same kind of division between the light-duty exposure circuit and the heavy-duty motor and shutter circuit.
Such design was typical for the early Super/Single-8 cameras.