Douglas,
There are actually a number of artifacts along the right of way. Nearly every steel bridge remains, There is a water tank and bridge in Navajo that was reciently repainted (the bridge was used for the road until a new bridge was built). A few weeks ago I traveled along the right of way down into Gato, most of it is visible, with the exception of a few places where the river washed parts away, or where the road was driving on it...
This is why I suggested someone trying to atleast tend to what was there. Speak to the Indian land owners and try to get permission to save Gato, the cars in Dulce, and Arboles. Even then it shouldn't take too much to do, if you have permission go for it. I would even do my best to come out from California to lend a hand.
-=Andrew=-