Sorry Mark, but I lived through that era...and they were anything but reliable.

The gunpowder type heating element often had to be relit, and quickly, or the repair was uneven or leaked. Moisture no doubt had an ill effect on them.

Great care had to be taken with the clamping mechanism as it was cheaply made and could slip, ruining the patch job.

If the hole in the tube was too large, the patch would bond to the opposing inside surface of the tube, rendering it useless.

I would guess that the death knell for this type of patch was that it took more time, skill, expense and luck, and in the end was no better than the up-and-comer glue patch kit which was cheap, compact, lightweight, fast and had a shorter learning curve.