Check out TekLager. They're Swedish, and I've bought a router from them before - excellent build quality. I think they make or made several themselves, possibly from pre-existing designs (unsure how open source the hardware is.) They can come pre-installed with various open source OSes.

https://teklager.se/en/

Not affiliated, just a happy customer. If you're thinking of getting in a similar business and are not a competitor in Sweden, drop them a line. When I spoke to them they were very friendly.