Will keep the US Mail from being delivered. At least back in the 50's.
A couple years ago, I embarked on a project improving a GGD PRR baggage car. Their product is modeled after a BM70ka baggage, the most numerous version on the Pennsy. I found the underbody needed extensive re-working as did the roof. Which was the incorrect profile. I corrected the roof by adding multiple layers of sheet plastic, sanding, filing and filling until the correct profile was reached. (something I hope never to do again!) I added clerestory windows, roof braces and vents.
I built and added correct PRR trucks from a PSC kit.
Unfortunately the lettering was in the wrong location. And trying to remove it bolloxed the paint job. So a repaint with Scalecoat had to be done and new decals added.
I had always wanted to add an accurate RPO interior apartment. I learned that Delta Models was going to produce interior kits. I offered to send copies of drawings from a RMS spec manual I had, and eventually purchased the kit from them.
Having the floor plan of the 30' apartment and a copy of the PRRT&HS Keystone dedicated to RPO cars gave me more than enough info to tackle the job.
These are pix of the completed job. The progress pix are rather boring.