Thanks to Andrew Tuckwell's reference to the James Watt display at the Science Museum in London, not only is the Ceramics Studio which was renamed a Pantographics Carvers Studio now correctly identified as holding a carvers pantograph, but more precisely it's an albumen print of James Watt's workshop.
On the left is the print in my collection. On the right is the image owned by the Science Museum, whose rights of ownership I so blatantly trespass upon in the spirit of academia.
Compare the two and the similarities and differences are surprisingly clear. I have no clue when the albumen print was made, whether during Watt's lifetime are after his death. I do intend to contact the Museum to let them know of the print in case they lack a copy in their collection. Not that I would release the orginal to them, but I would be happy to send a high resolution image...
Till next, Gary