let's see here:
The Weaver model represents a Budd-built car. Wrong.
The Weaver car is slightly short.
The Arrow did not have a streamline baggage car: http://www.trainweb.org/fredatsf/powhat49.htm
Plans for the Arrow cars can be found if you search long enough; I believe Prototype Modeler published them, e.g. The original, 1950 Arrow had seven cars.
Here is a floor plan for one of the coaches: http://www.trainweb.org/fredatsf/powhat49.htm
Anyway, it's your hobby, so can do as you like.
