Antique French Military Officer, Empire or 2nd Empire in 18k Gold 2-Sided Locket Frame

Actually, the painting is pristine and undamaged, and the entire frame in 18k gold tells us he was someone important, but the glazier (glassmaker) who crafted the 2 panels of thin convex cover glass for this one wasn't quite as good and it is what we refer to as 'sick' glass. Almost a flaking look to it, and it's pervasive on this one, rendering it more difficult to see clearly, as well as hurting value. Still, a 2 3/8" 18k gold locket frame and military portrait are valuable. When I found this one in France, I thought I would go to a local university which has glass-blowing and see if I could commission glass to fit as replacement. I didn't try to open it until later and I have not yet found it possible. I'm not one to pry hard on gold lockets. Plus there remains a haunting beauty to this one. Frankly, the 18k gold frame makes me think Napoleonic era, but the gold punch marks are so minuscule on this one, I can't begin to accurately date it. It might be Napoleon III era, and perhaps a