I would have guessed early '70's GM anf quite possibly Buick in particular, but the Holden or Opel connection is posible too. kinda ha a '69 Riviera nose while the roofline resembles a mid '70's 4 door Electra/98.
In my opinion, the Rangoon Red looks correct and it does have a hint of Orange. It was also a very popular Factory color for the 1955 Chevrolet and should be readily available thru MCW or a host of other sources. The car would have ran Firestone tires typical for the times.