Old time photographs of the engraving machine in use:
The first picture shows a production enviroment where those engraving machines where used a lot to do milling and engraving operations on a lot of parts. In this case, the machine is setup with a nice steel master template and the drum engraving attachement, as there are round parts engraved on the outer diameter.
Note the two machinist/engineers on the second photograph that seem to test the geometry of the pantograph mechanism with something that looks very much like a oldschool variant of the ballbar test that is done today on cnc machines. In the background a row of Deckel Fp1 toolroom milling machines without a vertical head can be seen: