I have one of these units, and it went pop on me, so I had a poke around inside.
In my case, the ESC lost reverse, so I suspected the output transistors. These turned out to be fairly modest BJT's, not even mosfets, with no heatsinking so probably unsurprising I smoked them (running 2s lipo).
I'm not a collector or purist, so elected to exchange the electronics for something a little more current. I used a miniature 4-channel orange receiver and Thor 15 ESC with a servo amplifier from a mechanically knackered servo to replace the onboard unit. It all that fits easily within the footprint of the old CPR unit, and the original servo is retained (it's a bit of odd shape as I'm sure you know).
Result is a much nicer car to drive, smooth throttle, more power to the motor and the benefits of 2.4ghz R/C.