Factual error: The 'Post Office' is nothing like an English one would have been, even in a remote rural location in Victorian times. It seems to have been transposed from the American Wild West.
Factual error: The persistent cascade of leaves underlines the poor condition of the house, but where are they coming from? The woodland in the distance already looks bare, and how are so many leaves managing to stop above and drop directly through a relatively small hole in the roof?
Continuity mistake: In the last scene outside there is a lot more machinery assembled than the one engine Sir Thomas was working on.
Factual error: Late in the film, we see both close-ups and wide shots of Sir Thomas Sharpe's "infernal machine" (a preposterously fictional clay-mining device) that is scooping bucket-after-bucket of oozing, bright-red goop from a horizontal trench. Problem is that the buckets come straight out of the ground and are conveyed by vertical chain up to a pulley mechanism at the apex of the machine, where the buckets then flip upside-down before descending back to the trench below. But nothing falls out of the buckets when they flip, the buckets are not dripping red with muck, and there is no hopper to collect the contents of the buckets, anyway. So, this massive prop is not mechanically correct nor practically functional, and it simply doesn't do anything. It's just eye candy.