This Sachs-Huret Rival ARIS is a presentable, solidly constructed and reasonably effective unit. It has its cable clamp bolt mounted on a sprung arm - to give what Shimano called a 'light action'.
In fact, compared to a Shimano Light Action derailleur of the time, the Sachs-Huret Rival ARIS was just slightly later to market, just slightly more expensive, just slightly heavier and indexed with just slightly less accuracy. It's cruel to say so, but it was also just slightly uglier.
It's tough competing against a highly capable, 800 pound, gorilla like Shimano.
This, thoroughly battered, example displays the following features:
I am very unsure about this derailleur's model number, partly because of its white finish, partly because of its early logos, partly because of its late date and partly because of its low-budget hex headed cable clamp bolt and pulley bolts.
Finally I should note that this was one of the most difficult derailleurs to clean in the known history of the world. It was solid with a black substance that was considerable tougher than tar - and I was loathe to soak it for long periods in any aggressive solvents because of its soft white paint and delicate logos. I can only apologise for the grime that you can still see on it - what you can't see is the matchbox full of black epoxy-resin-like-gunk that came off it!