Re: "milled somewhere that doesn't also handle wheat"
Oh Homer may be overstating the case, but not by much from what I'm told. My best friend was from the US and when he returned his sister prepared the family a Thanksgiving feast "from scratch". Almost everything was processed, even the potatoes. He said he couldn't wait to return to Tasmania and have a real feast at my place. The chicken came from the hen-house, the vegetables from the garden...
When the American artist Alan Gussow visited us he remarked on the rarity of food such as we served up in the US. Vermont market gardener Eliot Coleman remarked that small-scale market gardens like his are extremely rare. I frequently browse the Internet looking for recipe ideas. A very high proportion of those posted by Merkins include proprietary processed foods, even such simple things as a vinaigrette.