I think most chronographs are complicated watches due to how many parts the movement has and some watchmakers wont touch them due to there harder to work on. Here are three issued bunds issued to the German Air Force after WW2 during the 1950's to the 1960's and 1970's. The Junhgans J88 then the Hanhart 417 and then the Heuer. The Hanhart and Heuer both have fly back movements were you press the second pusher when the chronograph is in use and it resets and restarts. They were used for navigation.