In the American bike market, the difference between AD and Puch was simply one of branding and marketing focus. Both labels were made by the same factories. The AD line was marketed as an "upscale" line while the Puch label was marketed towards a broader market in lower price points. Both AD and Puch made some entry level models that were, quite frankly, crap . . . or at least compared to comparably priced Japanese bikes in the era. Both AD and Puch however, also made nice bikes and AD produced models at the very upper end of the market whereas Puch did not. The Vent Noir the OP originally asked about, was an AD model that evolved through a couple of iterations and over several years. The matte black version was the earliest as I recall and was equipped with Shimano Dura Ace components. The Smoked Chrome version (imagine chrome plating with a brownish tint) was a newer model, but I don't remember how it was equipped. Above the Vent Noir was the Superleight and then a Team version. The Superleight was a creme color and the Team version was a dark purple. The AD Interclub (I might have this model name wrong) was a burgundy model equipped with quite functional, but modest components. It was however, a full Reynolds 531 frame and the least expensive full 531 frame available in the US in the early 1980's.

I owned a bike shop in this era and sold both Puch and AD next to each other, intertwined to cover a range of price points. I also sold Fuji then and Fuji was the better line for entry level buyers.