We have dated the CDV based on a detailed blog post on ArtPlastoc that provides biographical info on Gasquet and indicates that he was at the address listed on the back of the CDV at that time. According to that article, Gasquet was a gunsmith and armorer who opened a photography studio in Cannes in 1866. He "produced views of Cannes and its surroundings but also of Nice and Monaco...and studio portraits against the background of large painted canvases showing views from Cannes (Le Port and Estérel, La Croisette and the Islands)."
This is a mounted albumen photograph. Measures about 2.25" x 3.75" on a slightly larger mount. Beautiful condition.