Hi
I happen to work for the company that still make the modern version (Bernhard & co). The cylinder or real is mounted in the two bronze bearings and slowly rotated and the grinding wheel is rotated and moved along the large slotted shaft. One of my jobs is to put the slots in the shaft of the modern machines, if you can find a serial no we have all the order books and should be able to find the manufacture date and customer.
Hope this helps Paul