Pocket watch: unique, extremely rare "Mysterieuse" in gold with enamel decoration, original box

Ca. Ø54mm, approx. 96g, original gold case, signed and inscribed "Mysterieuse", glazed on both sides so that you can look through the watch without seeing a movement, hands driven by rotating discs, crescent-shaped movement is located directly under the crown in the concealed area, in working order and in very good condition with original box, extremely rare. The manufacturer Armand Schwob & Frères in La Chaux-de-Fonds brought this curious pocket watch onto the market around 1888 and had it patented under the name Mysterieuse. Almost all examples had silver cases. Only a few were made in gold for special customers. To the best of our knowledge, this is the only example with an enamel decoration, in this case the name of the buyer Jose Pietranera. Jose Pietranera Ravina was a very successful businessman in Argentina. As the company Armand Schwob & Frères went bankrupt in 1892, these watches were only produced for a period of 3 years and are therefore very rare.