Antique French 6-Draw Opera Glass, Telescope, Monocular, Napoleon Era Vernis Martin Barrel DeBruyn which might be how the

which might be how the glass was broken

heavy and in its original leather presentation box or etui

Professionally restrung and preserved thus

we can confirm there is a slight warp to the lid (see detail images) and that slight warp of the old wood

The painting has a look of having had someone use a wet cloth at some point to clean outer glass and box

Antique French 6-Draw Opera Glass, Telescope, Monocular, Napoleon Era Vernis Martin Barrel DeBruyn which might be how theI imagine this was originally found at the boutiques of the old Palais Royal promenade, the little stars all around and the hand painted barrel in layers of paint and varnish giving it depth and added appeal and value. That method is routinely called, "Vernis Martin" after the brothers Martin who invented it. A method much loved by Marie Antoinette, but I digress. The compact opera glass, surely a gentleman's, would collapse and tuck into a pocket.