I'm in the process of servicing this for a relative and have noticed that the escape wheel lower pivot is broken - I suspect that this is why it hasn't been running for about 50 years. So, ideally I need to source a replacement - the problem I have is that the movement has no obvious manufacturer or Caliber marks - other than those that I've mentioned below.
The movement itself is stamped with the word DÉPOSÉ and the numbers 6 and 9 together. There is also a number on the movement and, interestingly, the case - it is 55709.
The ratchet wheel and the crown wheel are, unusually - well, in my relatively limited experience, both secured through the arbour by a sliver of what looks like brass, rather than a screw.
Any guidance would be hugely appreciated.