Colorado Rail Annual 1970, page 6, the excursion flat car with the planks for seats, is an AT&SF flat car. In the rear, pushing it is Profile & Franconia Notch "Echo", purchased by the Santa Fe. There is a photo of it at Canon City, but do not recall if or where it has been published
Denver, South Park & Pacific, M. C. Poor, Memorial Edition, page 183, Buena Vista Transfer yards. You can't seem them in the book, but in the original photo you can see there are a couple of AT&SF box cars in the back ground
The Santa Fe sold 50 box cars to the D&RG, and leased the rest of their narrow gauge equipment to the South Park for about 6 months. After 6 months the DSP&P purchased 6 Bowers, Dure passenger cars from Santa Fe