How to open Kay Speed Demon

[Stadler Guitars]

I'm dragging this old thing up to ask if anybody knows about the truss rods on these Kay built bolt-ons. There is a little 6-32 threaded rod with a 1/4" nut in a recessed ferrule at the back of the heel. Did these rods ever work?

[Possum]

....

The wax in those things seems to melt at a much higher temperature than paraffin, you need to heat it up pretty good to get it open. I have a couple dead ones but never rewound them, they don't really fit in anything but the guitars they came from....