curta type 1, serial#53256, purchased by my father in 1955 or 56 I believe, for day to day use in his job as a professional land surveyor. It is worn in the places you would expect from every day use but nonetheless was well taken care of. Comes with a heavy duty leather case that the curta can fits in perfectly. I dont know if you could buy this case as an option but it looks professionally made; it has a belt loop so he could carry it with him in the field. Best offer over $800.....thanks