This movement is inside an incoming 1970's JAZ 17 jewel dateur:
From just the balance cock it looks distinctly like a Parrenin, see the Parrenin HP 60 in my Ultra Racing for example:
Nothing like the JAZ movement shows up in Mikrolisk or any other of my references as far as I can see. I have copy of a document produced by the Swiss for their Douaniers in 1972 listing EU ebauches of comparable status to Swiss movements of that time. In this there's reference to a Parrenin HP741D, which fits the bill from the very basic description, but other than that I can find nothing at all. Any clues, suggestions or ideas would be most welcome.