Result

First drive test

The engine doesn't run smoothly, I feel like it has to much fuel... Plus, after 500 meters, the throttle cable breaks!! Argh, gotta push the beast back home...

I change the throttle cable for a Teflonized model... The "too much fuel" issue looks like coming from the needle valve on the carburetor that doesn't close correctly... With some patience and polishing paste, I adjust it, looks like it works... I reassemble it back.

Second drive test

The engine starts first kick, and runs smoothly... I'm a bit scared to go too far from home... but finally, everything goes fine!! I still have some gas leaking from the fuel tap, the speedometer cable that broke... But it runs fine, and I go for a fifty kilometers of pure pleasure cruising!
The beast is relatively comfy (well, gotta admit that after 1 hour driving on bad road, it becomes very relative! :-P). The gear selector is a bit delicate to use, but I got used to it quickly (I now understand the need for that needle indicating the selected gear on the gearbox!). Feels unstable at first try, but this is a false sensation due to the spring-mounted saddle and large diameter wheels...
Obviously, it doesn't drive fastly : given for 75km/h in 1954, but I don't think I drove faster than 60 or 65 km/h. Cruising speed only!
And the beast is a preu eye-catcher : people are either interested, curious, mocking, or envious, but everybody turn their head when it passes!

And voila! One more is back on the road... It deserves a new paint, but for now I want to drive it a few kilometers!!