I’m not sure I can answer this with the usual detail the other experts here do, but I’m writing a book about round, flat bread, so I went back in my notes and found this reference. Essentially, they were flattened by hand and cooked on stones, But the dough need not be very sticky-and a won’t stick to a well seasoned press. The Mayo (native to northern Mexico) preferred a white corn, and didn’t always use pure corn, often mixing in ground cactus seeds, so the dough consistency wasn’t always quite the same. They also weren’t squashed as flat as commercial tortillas (which IMHO are inferior in taste and texture) and were more like Indian fry bread. Here’s a great book on the subject. Even now, rural homestyle tortillas are made bu hand, or on coop equipment a whole village uses.