A friend of mine brought an old family watch to me to look at and tell him what he had. I was able to tell him a few basics, but would like to know more. It is a minute repeater with simple start/stop/flyback chronograph. I have not seen a movement layout like this one before. The only marking that is visible is an outlined cross under the balance wheel with the number "4252" inside. The case bears 18 carat Swiss markings and was assayed at Le Locle, but has no other marks except a 4-digit serial number. Is the movement distinctive to a particular maker? Am I correct in interpreting the marks around the edge of the dial as counting in 5ths of a second? What would have been the purpose to that?