I can now reassemble the body on the chassis.
The wires are soldered in the right places, then slid under the roof.
You can see the tank cover being put back on.
Note: I have left the lamps on, although the coach is not configured to be at the back of the train with its bellows unfolded.
View from the van side, with incorporated tail lights.
View from the compartment side, with removable lamps.
… And just at this moment, I noticed that the wires were still visible through the small window on the right. The partition will have to be put back at this place.