Train Car shell was built by Romagi1 and can be found here: https://www.thesims3.com/assetDetail.html?assetId=9357287
Pullman Car E329 “Pearl”
Shell by Romagi1 
Overview, 3 double bedroom sleeper car 
Hallway 
State Car #2 contains four Twin cabins, I used this plan as a guide. My version only has 3 twin cabins.
These are some reference picture of it’s interior.
More information about the collaboration can be found here:
JessaBean Sims 