BETHLEHEM, Pa. – Vaughn Randall squinted behind wire-rimmed glasses while seated on a bench in the shadow of his winning sculpture outside the Bethlehem Visitor Center at SteelStacks. His “Locus” – a five-and-and-feet-in-diameter, 1,000-pound, cast-iron and bronze, pinwheel-looking creation – rested on a black pedestal where it will remain…