Stumped: Toyota CV boot clamp

[zzyzzx]

I would just use a GSP replacement axle.

 

[Nukeman7]

OK, hear me out.
This is my working theory:
The yellow line is the fulcrum point that cams the tail over, the blue line is the side of the notch that interfaces and locks over and onto the red line (they're both straight cut faces where the lines are drawn).

I think we can all agree this is a correct assumption.

But somehow I've got to get the end of the tail (purple line) under the two smaller tab guides (green line).

I think it is much simpler than you are making it out to be. If my interpretation is correct, your references to the purple line and green line are not pertinent. The clamp is pre-sized to fit the boot where folding the (blue line) groove over the (red line) bump will provide the correct amount of tension with a minor bit of adjustment possible. Then you bend the two upright ears down to capture the tailpiece.