"Let's Stay Scientific With This Cabasson Paris Glasses Pantometer"
I look knowledgeable??? Not so much, I just learned that this superb surveying measuring object is called a spectacle pantometer, since it is topped with a telescope. Graduation of angles. is infinitely precise. I wonder if well cleaned, the flashy brass of this instrument would give it even more character, it's up to you.. 
Le Magazine de PROANTIC
TRÉSORS Magazine
Rivista Artiquariato