You could try this site where I I bought the Quinting invisible watch, the QSL55, (which I love) its a luxury gift site not sure if they do second hand but they might take the watch if it's in pristine condition.
I rather like the old Lip divers watch, they may have missed an opportunity but their design stands out. I recently bought the last Lip LCD digital gold watch on and I love it. Actually it was a good investment too, though that's not why I bought it. It doubled in price, in fact I was offered over