ACC has been around since at least the later 1970s or earlier 1980s. I first saw their booth at a high-level Corvette show in Dallas, after reading about them for several years. That was about the late 1970s. I was impressed with their carpets and how well they were molded to fit the floorpan. In a time when "molded carpets" usually had a covered seam down the middle of the front of the transmission hump.
I have similarly watched as Legendary Interiors and YearONE have grown from modest operations of correct OEM repro parts to what they now are, too. Once past these industry leaders, there were also smaller companies which did equally as well, usually, but with time and other things, whose operations were to later become part of the larger organizations.
End result, ONE company builds things that many OTHERS sell, although the large companies still sell direct to customers, as always. Just as SMS probably sells fabrics and vinyls to Legendary to sew their products with. AND auto parts are no different, either!
In one respect, these combinations have probably helped increase the quality of what is out there for purchase. The downside is that customer service reps on the other end of the phone line can know less about what is being sold, as a result. I used to advocate that the closer you can get to the base supplier, the better the customer experience can be, but various factors can thwart that orientation, by observation. So, shop price, service, and availability.
Decades ago, I was looking for some KONI shocks for one of my cars. I read the adds, but when I'd call them to see about ordering them, I soon discovered that what was being advertised was just a "drop ship" situation. NOTHING in stock in their warehouse. I got the best results with a larger re-seller (who had them in stock) and never looked back.
Just some thoughts, observations, and experiences,
CBODY67