I have more info on the railway scenes. They were all shot on the Embsay and Bolton Abbey Railway. A black loocomotive was specified and as there were no suitable black locos there and the owners of any that were there that might have been made suitable were not prepared to have them repainted, the E&BAR hired Sir Berekely from the Middleton.
The carriages used were some of those restored by Stephen Middleton at the railway. A considerable amount of work was done by the filming company to remove modern fencing and replace it with period materials as well as building 2 or 3 new wooden crossings of a beck. I was told how much some of the "dressing" work cost so I am not surprised that advertising seemed to be maximised!
There is one locomotive, currently in running order and operational, that was built before the dates of the story. It is Furness Railway no 20 an 0-4-0 tender loco, built by Sharp, Stewart & Co in Manchester in 1863 (works no 1448) . However that would have been completely wrong, design had moved on greatly and most contractors used tank locos. The outline shape of Sir Berkeley is right, the Manning Wardle design keeping many traceable aspects.
Other locos that could have been used are few, Belerophon, also owned by VCT is slightly older than Sir Berkely and currently operational. One that would have been operational near the time of building the Ribblehead viaduct is Hodbarrow (HE299) built by Hunslet in 1882 at the next door works to Manning Wardle on Jack Lane in Leeds. It worked at the Hodbarrow Mining Co in Millom. A preserved loco that would have been around towards the end of at the time of the building of the Ribblehead viaduct that is of the sort of size etc that most contractors had, is Black Hawthorn no 6 built in 1874 that is in the National Railway Museum in York but is not operational and is in conserved condition.