Color perception can be subjective, and the color images fom the era may not be accurate. The boiler jacket in most color photos/postacards appears (to my eyes) to be a great atempt at mimicking Russia Iron. Our own David Fletcher ("Fletch") has mastered the color, as can be seen here:
http://4largescale.com/fletch/d14a.htmLook around his website--it's pretty amazing, and his talent is museum-quality. I believe he uses Testors "Metalizer" paints; I'm sure he dicusses the color somwhere on that site.
The reds on the wheels/pilot/headlight and sashes is different. I trust you've seen this thread?:
http://www.burnsland.com/disneyrailroads/viewtopic.php?f=8&t=3158