This is a Lorenz JeanRichard/Aquastar. The most sought after 1581 model from the late fifties early sixties. This is the exact same model and configuration that was recently sold at auction for 100k$ and which was worn by Walsh down the Marianatrench. The serial number is even lower than Walshes watch. See the Blinkco article "The Journey of the JeanRichard Aquastar Dive Watch to Auction". JeanRichard made these watches double branded with Aquastar, and made these in addition with the Lorenz brand for the italian market. This watch has real heritage and is one of the earliest divers along with Blancpain and Rolex. The watch has been fully serviced by a professional and certified watchmaker, who also replaced the crystal and filled in the embossed indices and numbers at the rotating bezel. I have worn it on a Tudor NATO strap, which fits the patina on the indices perfectly. The hands were relumed to fit the color of the date window. In all, a perfect and highly comfortable watch for daily wear with historical value. Although the watch measures 36mm, it wears more like a 38mm. Apologies for the pictures. I am a collector, not a professional seller. The pictures do not do justice to this fine watch.