Very few make anything or even dye their feathers. When you see JS and a lot of others selling the Hareline Feathers and other products it's because Hareline is a wholesale company like WAPSI and these guys do dye dye their feathers. However I doubt they dye everything they sell, like rabbit fur, I doubt they do much of that themselves. They each have thing that make them popular. One example is Hareline has very good products and their feathers are usually the best you can get for several reasons I will not go into right here. There are not a lot of these companies, but there are a ton of fly shops and all sell materials for tying. Even most places you buy materials do not do any of that themselves, but a few like Crazy Angler and Cascade Crest do dye some items and probably Cascade does more of that since Crystal Antron is their baby.
So many things that look the same are not like Ultra chenille and some use different names for something close to ot, but many are just not the same thing exactly. I know that is confusing as I said it, but don't want to write a book here, LOL!