So what is this mystery tool?
It's the same thing as the "specialty" tools I've mentioned before. That is to say, if I told you what they were, they wouldn't be a mystery or a specialty anymore.
This is the kind of thing I sell on either eBay or sometimes cList and since people from all over the country read the forum there's no point in giving the competition any ideas about buying and listing a similar item. In this particular case there are already a half dozen listed (if not more) but they are spread throughout the USA and my hope is to grab the person who is willing to drive a couple of hundred miles to get this one as it is HEAVY...two parts totaling almost two hundred pounds. None of the other sellers are willing to ship either.
I will give you this though in regard to "specialty tools"...they can be used by any number of types of people from, car or aircraft mechanics, lumberjacks, ranchers, construction workers, muscians, hobbyists, theatre performers, etc. They all use specialty tools and some of them are semi-rare in our used world.