Dennis encouraged me to post this one. My wife came back from France in January with her grandfather's JLC DuoPlan. He was a design engineer for Fiat after the war and must have purchased this around 1929 when it was first sold. He died in 1933 from effects of gassing, and it was stored ever since. The watch was sent to Le Sentier in the mid 90's and the mainspring, dial and band were replaced with a full service. It is the mid-size version, but still very small. The beauty of this was the layered movement to fit in the small case. The layering allowed for a larger balance, separated from the other workings of the movement. It really is a remarkable piece of engineering that he must have appreciated. It was also back set, as you can see from the photo, that made for an elegant front appearance. I knew of the design, and was really amazed when she showed this to me--wore it home on her wrist--good idea!
Yes, pull to set, turn to wind. Unlike some later women's back set watches, this one is completely concealed from the front. They were in to the engineering and style to go with it. JLC is a very interesting company; they made some really interesting watches. I have a Futurematic, as Dennis knows, that's a wonderful watch as well, but mine is a US cased model. This rarer and mainline JLC. They seemed to love engineering complications.