Fantastic, and how refreshing to find an enthusiast posting up silent film left silent, rather than over-dubbed with fake background noise or - even worse - stupid music. Well done old chap!
The leading coach in the train at 1:53 is interesting. Looks like an ex LMS but in the blue and grey modern image corporate livery. The rear coach looks similar but is in maroon.
Because the original was 8mm cine film. In those days you could not record sound on 8mm cine stock. Sound could only be dubbed on from sound recordings which were few and far between, as portable sound recorders were rare and very expensive. Not many recordings exist from the early 1960's.