You just need to follow the basics, and the most basic is that you've just been f*cked-over, big time.
The second most basic rule is that Pascal and Henri rode this fine machine for many happy miles, and then another rather unhappy 100,000 more, and the poor old dear really needs to be left in peace now, preferably as wall-art in a chic bijou French restaurant, but if you must try and actually make that silly little engine run, then follow the third of the most basic rules, ie le spark, l'essence and le timing....and if any of those is missing (along with le saddle, le mudguards and le big chromey lever thing to make the engine turn) then disappointment sadly awaits.
But never mind, just light a Gauloise and stare at the sheer Deco-ness of it, and try and block out that damned accordion music that plays in your head every time you have images of La Belle France..