I was looking at this beautiful starter cap on my bike and a thought occurred to me. One of the irritating things about the ZA50 starter cable design is that you have to remove the cable from the starter lever in order to get enough slack to raise the starter cap to remove or adjust the starter where it attaches to the motor. Since the cable is pinched into the lever it is inevitably frayed when you do this. Sometimes if you solder the cable end right you can reuse it but a lot of times it's too frayed to reuse.
This aluminum cap is much stronger than the stock plastic cap. Probably strong enough that a vertical channel could be cut down from top to bottom, just wide enough to allow the starter cable to be extracted if you popped the cable housing over the seat at the top of the cap.
This channel would allow you to remove the cap without removing the cable from the starter lever, make adjustments, and pop it back into place...