Folks,
I very much doubt that many railroads made a deliberate attempt to preserve their steam locomotives. Exceptions being the SP and UP.
Certainly the New York Central=1, the New Haven=0 or the D&RGW=1 all thanks to President Perlman!
Th exceptions came about because they were sold to other lines. Take the New York Central # 3001(Schenectady, 1940) at Elkhart, Indiana. She was hiding under Texas & Pacific # 909 for years before J. David Conrad (I believe) moved her up to the National New York Central Museum.
We have covered the story of the D&RGW #685. Sorry about the standard gauge stories but they are too good to miss.
And the loss of the New Haven locos has a happy ending; the Essex Steam Train has taken a Chinese import and made it into a convincing replica of a New Haven freight locomotive.
I do no have the details at hand; but i think it is a 2-8-2.
Ted Miles