The Pennsylvania Railroad was one of the most resourceful companies in the US, manufacturing many of their own locomotives in their infamous Juniata Shops. They also built their own freight cars using stock parts and their own designs at the nearby Holidaysburg Car Shops. In the early 1950's, the Pennsy manufactured the X44 design, a 50' boxcar very similar to standard USRA designs. The cars were put into general service, but as the finances of the railroad deteriorated and Penn Central appeared on the horizon, they sought to sell off older rolling stock in favor of new designs and larger capacity cars.
Coincidentally, in the early 1970's the Delaware & Hudson, a smaller railroad running mostly through eastern NY and PA, needed 50' boxcars to replace their aging 40' fleet. So, in 1973 the D&H purchased around 50 cars of the X44 design from the Pennsy and brought them to their Oneonta, NY shops for re-manufacturing. The cars had a variety of modifications including new reinforced sills, some getting lowered brake gear, new doors, and all having their roofwalks removed. The cars ended up in a couple of different paint schemes also, between white or yellow lettering. They were placed into general service and likely lasted well into the 1980's.
This model is car D&H 25051, seen in the D&H Color Guide in brand new paint in September 1973. I modeled the car is it might have looked by 1980, with a lower quality paint used in the 1973 rebuild, and reduced maintenance as time went on and the railroad started running out of money. This started as a Branchline Blueprint Series car, the PRR X44 model. I followed the prototype photos for the modifications and cut down the ladders all around, added a new sill, rebuilt the ends with lowered break gear and custom ladders, and added etched metal brake platforms. In looking at other D&H cars of similar age and design, they didn't usually get crusted with rust, rather they just got very old and dirty. More than likely, the roof of this car got a token coat of paint or primer, so after only a few years the underlying decay and continued age would result in lots of rust and grime running down the side of the car. Additionally, this car served with original friction-bearing trucks through its entire life - so plenty of grease got thrown around especially down low on the sills, and then around the doors as well.
The D&H has one of the most colorful histories of any railroad around: It survived right through the formation of Conrail, taking a beating through the purchase and pillaging in the 80's by Guilford Transportation Industries, the federally mandated operation by the Susquehanna ( NYSW ) in the late 1980s, and purchase by Canadian Pacific in 1991. Still under the CPR banner and operating in the red, the railroad hosts a plethora of NS traffic now as part of the Patriot Corridor. But if you look around hard enough, you can still find cars with this older paint scheme stashed on sidings and used for storage. The shield and the slogan "The Bridge Line to New England and Canada" still holds true.