Was just watching an old Top Gear and discovered a man named Loewy.
He participated in the design of some amazing post-war engines for the Pennsylvania Railroad, including:
the K4s 4-6-2 Pacific (http://en.wikipedia.org/wiki/PRR_K4s)
The Broadway Limited from 1938-48 (http://en.wikipedia.org/wiki/Broadway_Limited), very interesting page!
The GG1 electric from 1934-43 (http://en.wikipedia.org/wiki/PRR_GG1)
The S1 6-4-4-6, the longest steam engine ever built, you must check this page! (http://en.wikipedia.org/wiki/PRR_S1)
And finally the T1, PRR's last steam engines (http://en.wikipedia.org/wiki/PRR_T1), made by Baldwin, as were most of the others
incredible designs, skins would be hard to recreate, but I'd be happy to help with the Hex editing if anybody is interested in skinning any aspect of this project...
But at least check the wikipedia pages I've linked, very nice for rail enthusiasts!