Yeah, they likely did wear tweed and spend a lot of time in the pub, try to remember it's a film. Something being a period piece simply means it's set in a certain time period. The help in Downtown Abbey probably wouldn't have been as well treated as they were in the series but it's a period piece all the same.

So your main gripes here are the 'picturesque' tweed and the fact they spent a lot of time in the pub. Okay.