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-7b, c, d, e); some engines were rebuilt and reclassified more than once. Here No. 5314, the former President Lincoln, appears in an undated shop photo after rebuilding to class P-7e. 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.