The J.C. Penney at GSP was a Stage II store, which encompassed 3 levels and 88,000 square feet. It opened its doors in October 1958 and was one of the largest units in the 1,692-store chain. Some of the store's features were a Singer Sewing shop, bake shop and gourmet shop. 
Drawing from the J.C. Penney Company

The Horn & Hardart Restaurant offered waitress service. It was adjacent to the Horn & Hardart Retail Shop, which was a self-service food facility. Dig those tail fins!
Drawing from the Horn & Hardart Baking Company

Gaulph Carpets was another original GSP tenant. The store opened its doors in October 1958.

Drawing from R.H. Macy & Company