Many thanks to Andres who gave me this shutter when we met up in August (2017),, it had some issues as there was no release mechanism. It's designed to front mount on a brass lens. Note the back cover has been removed to show the mechanism below.
It could be cocked and released with a screw driver through the hole on the front, or through the side. The original pneumatic release was missing.
Using brass tube which I threaded to take a cable release I made a simple plunger to trigger the shutter mechanism.
The new tube is bottom left and the cover is replaced..
The shutter is now fully functional, I need to test the true speeds as there's some adjustment of the shutter speeds, see the 1-7 scale on the bottom left.
The shutter is fitted after focussing just prior to use.
So far I've only found one similar shutter on the Internet with the number 513, but there's no details or a date.
"Le Mignon" seems to translate as The Cute, The Dainty, the name was also given to a camera of probable ICA origin but most likely totally unconnected.
So an interesting "working" shutter to add to my collection which is growing. Thanks again Andres.
Ian