Spent a few evenings to re-assemble the magneto. I had to order a new "Magneto Ground Terminal Assembly" as the original one was bent.
I found it on Harley (old type 1958-1969 XLCH) vendors. (Reproduction of 29626-55). I had to remove the new rubber (front side) on the magneto bearing : it was too tight and the rotor wouldn't turn easily. I've install the original one.
I got my first sparks !! However, it is quite weak... I plan on changing the condensor, maybe also the point.