In the Railway scene the "GWR" No.5 is actually former Lambton Collieries No.5, an 0-6-2 Tank Loco Built by Robert Stephenson & Co. Ltd at Darlington (Works No.3377 of 1909). The Lambton Hetton & Joicey Colliery system was part of the large colliery systems in the North East of England, a system so large it even ran its own passenger service.
This adaptation makes the usual error of giving Watson a Webley Mk VI .455 service revolver. Though it has the "look" of a 19th century revolver, it was not fielded by the British Army until 1915, almost thirty years after the story is set.
When the hound attacks Selden, during the struggle there are scenes in which the victim changes from Selden to Sir Henry Baskerville. Seldon's head is shaved, while in parts of this scene, the victim obviously has a full head of hair.
In this version of THE HOUND OF THE BASKERVILLES, Selden's braincase is held together with stitches because he has undergone a lobotomy. But that operation was not invented until the 1950s.
Sherlock Holmes: It may be that you are not yourself luminous but you are a conductor of light. Some people without possessing genius have a remarkable power for stimulating it. I... I confess that, my dear fellow, I'm very much in your debt.