@0culus:
Fun aside, about the threads again:
I do not have a specimen of the smaller threaded end now. So if it is this one that fits the probe, try to identify it. It might even be a widely available UNC thread and then we would only have to find a fitting set screw, maybe modify the tip and drill a hole or cut a notch for soldering to it.
Of the larger thread, I have some left. I'll look at them myself.