Prototype #2 works !
Time to learn French ;-)
Please note that this is a "demonstration unit" that uses a slightly different driving topology because the LED require higher voltages. The LED are only intended to show off (aesthetics matter !) and the series units will use the intended "dumb" germanium diodes.
The design of the diode array is now "right", the concept is validated and CAD should begin... "soonish".