Unfortunately, that film (the Underground Journey) wasn't entirely true to life - it claimed to be a round trip going in Meerbrook Sough, through the mines of the Gang vein, and out through Cromford Sough, which theoretically might be possible with a lot of digging out! However, it was filmed in bits and joined together, apparently some of the sequences were filmed in a quarry at night!
Dave Webb transferred the film to DVD a few years back if you want a copy, they're on sale at the museum....
Follow the horses, Johnny my laddie, follow the horses canny lad-oh!