However, in 1991 (A5307, Ext. 39/24V0) another modified Watt's link mount was homologated, which is anything but clear:
The description is:
"Platine c'ancorage de la jumelle de watt
Piastra d'ancoraggio del parallelogramma di watt"
Which means a mounting plate for the watt linkage. I assume it is a steel plate welded on to the de dion with at least 2 holes to bolt in another plate that holds the watt link axle at a desired position.
The question: Does anyone have a better picture of such a mount or is able to describe it in more detail?