In its heyday, Allentown, PA, was the home of Mack Trucks’ main assembly plant, a sprawling industrial complex in the south side of the city that straddled 10th Street from Harrison all the way down to the banks of the Little Lehigh Creek. For the past 20 years, however, employees in the 17,600 square-foot building at the southern edge of the property have been churning out a much different product: organic tofu.