As the Baltimore & Ohio's premier passenger power, the twenty "President" Pacifics of class P-7 underwent various modifications through the years. These included application of disc drivers, a one-piece cast engine bed, the Worthington type SA feedwater heater, and a headlight centered on the smokebox front in place of the usual B&O high-mounted headlight. (This was in addition to the streamlining applied to Nos. 5301-5304.) When rebuilt, these locomotives were reassigned to a subclass (P-7c, d, e, etc.) but online data is sketchy about which rebuilds received which subclass, and some engines were rebuilt and reclassified more than once. Here No. 5314, the former President Lincoln, appears in an undated shop photo after rebuilding. The image below, from the 1950-1952 Locomotive Cyclopedia published by Simmons-Boardman, shows the locomotive bed with cylinders cast integral that was applied to the B&O P-7 rebuilds.