These blue-line prints look like they are from the collection of John Maxwell, who made drawings of a wide variety of both narrow and standard gauge rolling stock. He did drawings of Rio Grande equipment and for other roads as well. While not as detailed as those done by Pruitt, Darr, and others, they were considered a reliable go-to resource for dimensional data.
I amassed number of these for use in model building years during the 60's and 70's. I believe that the CRRM has a considerable collection of his sheets.
Ed Frey
Loveland, CO