A Pennsylvania Railroad Keystone Station sign for DR interlocking tower on the PRR Main Line between Altoona and Pittsburgh in Derry PA. NOTE: this object is KIND mesh. It is intended to be used in conjunction with one or more attachment points on another object. The geometric center of this sign's back is where the attachment will occur. Based on PRR Drawing Number 78160-A, dated 1926. Developed using Blender 2.79 and TANE SP4 (Build 105766).