Bought at internet auction without seeing the movement or watch come to that. Taking a chance I know but the case and dial was so good. looks like it hasn't been worn much and its got the guilloche dial I really like. Its got the hallmark and a squirrel so 14k solid gold but it is a snap back and I can't get the back off. working so well and keeping excellent time. The vintage watch maker I use is so inundated that he won't/can't take the watch in for a service for 6 weeks. Its frustrating not knowing the caliber and case and year. Anyone care to hazard an educated guess. This is only my third constellation purchase and I've never held a bumper watch. When i move this one around I can feel something moving akin to a bump so is it safe to assume that it is a bumper movement.