That's a great watch. I'm sure someone with more expertise will be along soon enough, but: you've got a Broad Arrow chronograph, more than likely running a Valjoux 7733 or something similar.
Here's a great example by LeJour; you'll note the case, hands, and bezel are identical to yours, and the dial's all but identical, minus the placement of some text. These broad-arrow 2-register chronos were fairly common, at the time, were made for a variety of companies, and the only thing that'd really change would be the logo on the dial (the same thing happened with other chronographs too, of course). On your example, you've got a Breitling crown, for whatever it's worth.
Anyway: it's a great watch. Wear it in good health.
