Based slightly on the NKP Pullman Cars 80-84, unofficially car 0.8
You will need 2 gangways & truck sides

fo43 made interiors for this thing (they are amazing): https://www.thingiverse.com/thing:7288867

Minor Chassis Update so that couplers don't sit too low, sorry I didn't catch that.
Update 2 I added a truck & truck adapter so you dont have to