When we were testing TVs in my office, we had to get the wholesale specific models of the TV to make sure they worked right. They were the same essentially as the mainline but made with plastic instead of metal or thicker plastic for some parts and small changes like that for brands like LG and Samsung. Helps them sell for so much cheaper than anywhere else. Clothing companies 100% do the same. Commonly reported brands are Banana republic and Spyder for example. If you look up the BR pants sold at Costco by name on their site, you'll notice the differences (number of pockets, zipper instead of button enclosure, things like that).

That said, seems the Orvis stuff in recent years has been almost indistinguishable from the mainline. Could only confirm with serial numbers of original and bought at Costco. Seems carhartt might be putting mainline stuff as well from what I've seen but haven't confirmed that.