Turners sells feed from
Tucker Milling - while they are barely in the last century as well, in terms of web design, they are a might better than my own Harrell's Milling Co.

Good luck in your search, you will likely end up using their Starter/Grower as your "all around" feed, plus free choice Oyster. I don't see a Flock Raiser/All Flock equivalent, but what I can find of their Starter seems to check the right boxes - higher protein, lower calcium, and I can't find numbers on the rest. If you had ducks, I'd say look at the Niacin, but...