They’re not making them anymore! OK, that’s a joke. But as our housing stock gets older, it’s harder and harder to find a midcentury home that retains its original features. I’m not exactly talking about architecturally-designed houses, though they are wonderful to see and mostly have remained pristine. Bucks County holds a number of mid-century moderns, though they can be hard to spot; the setting is an important part of the whole and they can be discreetly hidden. But once you see one, you can immediately identify it. Bauhaus Walter Gropius & Marcel Breuer house   Characteristics include natural building materials: stone and wood, and sometimes concrete. They are often single-sto…