As a historian, the historical reference innaccuracies have also annoyed me. The Victorian Era did not start until almost 3/4's of a century later, and the "heydey" of disco wasn't until about five years later. Quite often, in pictures that try to "capture" the reality of a certain time period, they get things wrong. That's because, I believe, movie studies (like most other corporations) don't find utilizing historians as necessary. Even the movie Titanic, where Cameron wanted everything to be "factual" about the voyage (he had the light sconces in the set mock-ups of the ship's First Class corridors replaced because they had the wrong number of screws holding them to the walls), there were several faux pax's, including showing passengers promenading and sitting about outside decks with no coats. The mid-Atlantic, in April, would not have been condusive to comfortably enjoying fresh air in nothing more than short sleeves. The scene of the star-crossed lovers at the very bow, enjoying the sunset, wearing just shirt, pants and a flimsy dress while in the blast of 22-knot April winds would have been more accurate if it would of shown them with their teeth chattering and bodies shivering rather than sharing a romantic kiss and embrace.
Gerard