Vintage WP&Y and RGS films *LINK*

About 15 years ago, a well known video producer released on VHS a number of old Blackhawk railroading films. A few films in particular had narrow-gauge themes and are favorites of mine:
"White Pass & Yukon"
"Rio Grande Southern: Trestles of Ophir" and "Bustling Narrow Gauge" [The video label actually says "Bustline"--Ha!]
The scenes are priceless and the black & white filming (even sepia tone, in some cases) renders a more palpable historical feel to the subject matter. The organ or piano accompaniment is almost as good as hearing live sound.
Blackhawk Films has a web site and lists some railroad films available on reel. I did not see any narrow-gauge ones. Perhaps a large part of the old RR collection is no longer available for one reason or another. I have noticed that a man by the name of Carl Dudley was involved with many of them. Can't find much about him except he was involved with Dudley Pictures Corp. and the introduction of Vistarama (Cinemascope).
Anyone know more about Carl Dudley and Blackhawk films with RR subject matter? Any other Blackhawk titles on narrow-gauge operations?