However, I believe you have listed companies that are actually distributors or importers. Boarder Patrol for example.
American Made Audio Products
I just came upon this and wondered if anyone else has seen this website. I try to support the home team when I can so this is interesting, at least as a resource, and not a sales tool. I apologize in advance if I’m late to the game on this but interesting to hear anyones thoughts, knowledge, etc. Thanks. https://americanmadeaudio.com/