Driving Tour of the Chili Line and Farmington Branch?

Hello everyone - I'm more of a follower of the forum and I really enjoy all of the great information and stories shared on here. But now I have a question (or two?) since my Dad and I are planning a trip out to Colorado in a couple weeks for another narrow gauge vacation - no it hasn't been our first one... In the past either I or both of us have had the pleasure of tracing the ROW of the Marshall Pass line, some locations along the RGS, and also the east and west approaches of the Alpine tunnel.

We've never traced the Chili Line or the Farmington branch though, and we want to do this while we're out there this year. We'll be driving a 4WD Honda Ridgeline, so can handle trails as long they're not overly extreme. So, this brings me to my questions...

Besides the main paved roads and highways, what would be the recommended roads / trails to follow in order to re-trace the steps of both the Chili Line and the Farmington branches as closely as possible?

Thanks!