Whoever produced the CD seems to have drawn from a variety of earlier recordings. One of which was a 33 1/3 rpm phono disc sold by a record company that specialized in folk music and the like, Folkways Records. I don't recall the actual title of the disc (I don't own it) but it was recordings of the D&RGW narrow gauge. One side was the Silverton mixed, recorded from the caboose cupola. The other side was titled "Three little engines and 33 cars." The second side was a Cumbres Turn. My recollection is that the recording was done by Vinton Wight. Unfortunately, the public library, which had this disc, got rid of all its lp's and went to CD's for its lending music collection, and I was not quick enough to get this disc at the record sale.
Good Hunting!
Charlie Mutschler