Hi, Rockpup!
Been doing some diggin' I see. Just now relocated your post and this photo. Been hunting for it for about 10 days now.
I believe from the distinctive knob you have on the left side of your photo, that you have about nailed the partial lorgnette lens frame to the correct time period. The protrusion on the upper right of your photo indicates there was "another lens" in my way of interpreting that photo.
Have you considered soaking it in mild dishsoap, and attempting to ascertain the metal? They made them in base metal and precious metal. I saw dirt and discoloration in your photo, but couldn't tell if it was tarnish or what, that had dulled the appearance of the lens frame.
Nice find, in any event.
Here's a photo from the 'net showing a partial collection that was for sale recently on the other side of the pond.
Kind regards
