Here is the iconic Seiko C359-5009 calculator watch. Stunning design although not all that practical to use. The was the second generation of Seiko Calculators the first being the C153 which I also own. This one came to me as a non runner and the battery had rusted in its compartment. However it appeared to have not leaked. All that was required to get it working properly was a very good clean of the case pushers and the circuity inside. Take a look at the photos, this was in a hell of a state and clearly had been worn and loved for many years. At least I can do it justice to bring it back into service.
Very proud moment when it fired back into life and is now one of my most worn LCD watches. I has a great alarm function and an hourly bleep which takes me right back to the 1980s