Thanks, that makes sense (I still don't recall seeing a third coach in Golden in the '60's, but it must have been there), but here's another two more questions:
What replaced the third coach (since two of them were replaced with new steel coaches 336 and 337, which ride on trucks of two of the retired coaches), or was this when the D&RGW decided on the one 10 car set and one 11 car set plan that allowed use of a private car as needed on the first train?
The second question is, where is the third set of trucks? Did the D&RGW keep a set in reserve, because they never came to Golden.