K-Line Passenger car floor plans

For my Crusader cars, I looked for pictures of the prototype to determine how the seating would be done.

I would be surprised if there were any floor plans but I could be wrong.

K-Line Heavyweight Passenger car interiors I believe were all built-up the same "at the factory" for each car type.  That is because the bodies for each type are the same regardless of Railroad since they are molded plastic (the same).  Your best way if you want it to be "as K-Line original" would be to reference a car of the type.  If you don't have one yourself, then if you know someone that does, look at those.  Otherwise if some on the forum has a car disassembled, maybe they can provide pictures for reference.

That being said, if you want better accuracy for a given railroad's car I would follow GRJ's and try to duplicate the best you can.

As far as K-Line Streamline extruded aluminum cars, they have may different window arrangements and different floor plans.  However, the interior arrangements usually are NOT all that accurate for a given Railroads car's, even though the exterior window arrangements might be pretty close.  This is compounded by the fact that most 15" and 18" cars are shortened versions of the Prototype car.

The example of this "that drives me nuts" is the Milwaukee Railroad Skytop Observation cars.  The interiors are built up to somewhat mimic the Olympian "Creek Series" sleeper cars, however the exteriors (including car names) are of the Twin Cities "Rapids Series" parlor car type.  So I plan to "convert" the interior.

That being said if you are willing to tear the car apart you can end-up with something "reasonably" accurate. One of the reason I love K-Line Passenger Cars.

K-Lines were designed to be mass produced at a moderate price.  They were not designed like Sunset/3rd Rail Cars to be prototypically correct.