I was in Amsterdam over the weekend and ended up in a fairly swish watch shop with airlock doors etc. Whilst we were in there browsing an incredible array of rare vintage watches a thunderstorm rolled in so the owner came over, offered us drinks and engaged us in a half hour long conversation about our all time favourite watches even though he knew we weren't there to buy. Having said that, if I'd had a couple of pints there were certainly a few watches I would have splurged on.
Anyway, during the course of the conversation he removed one of these from his wrist and opened the back for us. Ignore what it looks like and what it does. Just imagine what the movement looked like.