Over the past six years while returning back to the hobby after being away for 30+ years, I started to amass a considerable collection of digital photos of PRR and other RR freight cars.
I have photos of three different X26's in MOW service in gray or yellow paint. Hesitant to post them here due to possible copyright infringement. If you look on ebay, every once in a while you will find a photo.
I believe the correct term for these cars once placed in MOW service is "tool car". The Atlas model is as close as you can get but not exact. Once PRR boxcars were dedicated to tool car service, the shops typically added windows (one photo shows a car with 4 portholes and one with 2 square windows on each side) presumably to provide natural lighting so one could see better to find tools in the car and they also had a length wise step (double rung) at the bottom of the door to make it easier to get in and out of the car. Some had a man door inset in the large sliding door.
It may be a challenge to add porthole windows in the car sides of the Atlas model but a step along the base of the sliding door should be fairly easy to accomplish.
Bob