Thank you, for all of that wonderful input.
I realize that if I increased my target time frame to include the 1970's, I would be allowed a far greater abundance and latitude in rolling stock and diesel power selection.
I suppose my main reasons for not exceeding the 1965 time frame are these: I like a photograph I downloaded, captioned as taken in 1965, but, showing a 1960 Chevrolet CN pickup and a CN 3rd class depot in the actual town I live in. The depot is not there anymore, but, I have a set of well drawn plans to scratch build the depot, along with boxes of balsa left over from my R/C aircraft days, and a supply of basswood.
Also, I already own eight Oxford 1:87 vehicles representing 1956 - 1965. I may as well put them to use.
Besides, I really like the look of the older olive grn/yellow CN engines. There seems to be an available supply of those between Athearn, Rapido, and Atlas.
At this early stage in the game, thoughts on rolling stock are only occupying a small area of my pea-brain. What little is there is envisioning coal hoppers being pulled by green/yellow diesel, and winding through the forested foothills in the pre-Rocky Mountain area that is my home. I can see, that I have a huge amount of hobby work to do before I can successfully achieve what I want to do. Perhaps, a few years worth.
Guy