I don't know much French, but I know enough about 2cvs to tell you what he's done here. It appears to be the original chassis with the front and back "legs" chopped off. The suspention arms normally curve outwards away from the centre of the car, but the front left one has been moved onto the right hand side to curve inwards and give a central front wheel. The back right suspention arm has been flipped upside-down to achieve the same effect at the rear.
The engine and gearbox have been strapped to the chassis platform, just forward of where the fuel tank once went. The rear wheel pokes up through the old tank chassis appature and rests against the left-hand brake drum (mounted on the gearbox in this car) to provide a 'friction drive'. The differential has been disabled by jamming the other brake drum in place.
The bottom end of the steering looks to be made of a rearrangement of standard bits. I'm not sure what the steering column used to be, though. The saddle is made out of one end of the bumper covered in tape.
The original exhaust manifolds don't appear to be connected to anything, so this thing is going to be LOUD, and blow fume straight into your face