I have disassembled cleaned and reassembled this thing. I am very impressed with how well made this thing is but I am still ignoraant of its use and purpose. Here are some closer pictures.
The pink arrows shpw two claws facing away from the picture. These have controls to raaise them lower them and lock them. The device above and to the right slides across and also has cut out claws, engaged with the right hand lower claw i this picture The partial circle cut out can slide along the ways and lock down with the large screw..It can not pass the two claws that come up from below.
The raising and locking position claws raised from below for the have screw adjustments. The red arrow points Similarly the steel pointed above and to the left moves along teh ways and has a lock down screw. The tension on teh ways is adjustable with the steel gibb.
The red arrow show where a lever press the side claws against the working surface. Th wwhite aarrw show a pin ingtegral to the claw which locks against the screw which is turned via a hole on the side of the head
Thia view shows the lever for raising and lowering teh locking tab over teh side claws. The handle on teh :7" shaped devoce moves it into and out of the locking . The depth of the lock is adjsuteable via a small set screw at the end of the lever near the handle.
When I bought it I thought this might be a pallet adjusting device but there is no way to mount a lever without breaking it and and one of my expert friends dismissed this possibility.
As a size reference the width of the working area is about a centimeter.
At the risk of being laughed at, First I believe it is a watch makers tool. Bench made(of the highest quality) for a singular job. Perhaps to straighten,reshape or some other adjustment for watch size EW. Given the precision perhaps for chronometers.