Phil Kitch (MECUK Bagheera expert) tells me that the rear shockers were unique to the Bagheera and that is why they are so difficult to find.
Andy,
I'm not so sure that they were unique.
In the Simca Talbot Matra world, yes they are. But, I heard that they were similar to an Alfa romeo front shock model.
I have a pair of the DeCarbon so I can provide you a ref # if needed (front only) but they are difficult to come by.
A more easy brand to find is the Koni. There are several models but I don't like them that much. I have the fealing that they work only in compression.
On my black X 79, at the rear, I have Politechnic ones which are actualy bilsteins. The problem is to find the ref. One day, I can have a look. Don't by pelitechnic because the red paint hardly justify the price
Regards