The Midwest was the heart of America's prefab-housing industry during the first half of the 20th century. Aladdin Homes of Bay City, Mich., is usually credited with pioneering mail-order sales of pre-cut, relatively easy-to-assemble kit houses through its catalog, another innovation. Popular models included the Pomona, an Arts and Crafts bungalow that would have looked at home on any of the tree-lined streets of that Southern California city.