Probably worth Googling for "centre second chronograph hunter Chester 1886" for recent auction prices (although these are likely to be better-known names, such as Thos Russell or similar). That movement was made in the tens of thousands and I don't recognise the name on it (sorry). It'll be beating at 18,000bph, so each of the 300 markings should correspond to the seconds hand moving at 1/5sec. Nice thing.