Simply putting the current coaches on passenger trucks would improve the look (they ride too low) and improve the ride. Whether this would be worth the cost though is debatable.
Once the 4 historic cars are restored, building two San Juan type reproduction cars would be nice. They already have the RPO and there is an unrestored baggage car. A vestibule coach and obs only used for special occasions could be built to original specs but for everyday use, at least have a steel underframe and hidden steel structure at the car ends to prevent telescoping.
Michael Allen