I know I have seen diagram just like you need in some railroad books, so if you've got a good collection of books on your chosen prototype (or know someone/somewhere you can borrow books from) you may be able to find what you need there. The books may also have interior pictures which will be helpful I'm sure.
And yes, as previously mentioned the internet may have something! Railroad historical society websites may be helpful, they often have all sorts of random stuff!
Regards, Isaac
I model my railroad and you model yours! I model my way and you model yours!
Do an on-line search with "XYZ passenger car diagrams" with XYZ being the reporting marks. Works for PRR, NYC, GN, WP, CB&Q, ATSF, MILW, NP. B&O - every line I tried. Have fun !
Got yet another one for my Forum friends: Does anyone have a good diagram for the interiors for the following passenger car types (all lightweight): diner, vista-dome, observation and dome-observation. I've decided that I should make my passenger cars look like they are actually earning their keep. Given that most all the cars are Athearn I will have to bash them. The obs-dome is a Con-cor. As usual, thank you in advance for any assistance that can be provided.