Round £100 posted, which is the lower end of what they go for on eBay. I'm not sure of it's waterproofness, it had some condensation that I sorted by taking the caseback off but it is 40 odd years old (I think). Apart from the patina on the hands it's in great condition.
Any interest in this? Have a few too many pieces and it's just not getting the wrist time. (now sold)