Might I suggest one point of view for the whole "historical integrity" argument.
PARTS ARE PARTS
STEEL IS STEEL
Just because a steel wheel ran over Marshall Pass, Cumbres, the entire San Juan Extension, the Clear Creek branch, the Leadville-Climax branch, South Park line, all C&S trackage, over Corona, The Chile Line, RGS................or anywhere, in the end it is JUST A PIECE OF STEEL. It is not sacred, blessed by the Pope, or Holy in any way. It is a piece of metal which is a part of a larger machine, which in its assembled state is what is important - not the part itself.
That is all.
Shane