Continuity mistake: At the end of the previous episode, when Mei's father Ah-Tao dies she touches his face (after Buchanan joins the room) and she is wearing dark red fingernail polish with jewels. At the beginning of this episode showing the same scene, Mei no longer has polish on her nails.
Factual error: The steam locomotives seen are dull faded gray. The railroads of the 1800's had great respect for the trains that brought their business. As such, their locomotives (even those in freight or yard duties) were painted in vibrant colors, with their bells, whistles, and other brass components highly polished. The replica engines at the Golden Spike National Historic Site, as well as various other preserved 1860's and 1870's vintage locomotives all give you a good idea of how steam engines appeared during the show's time. It wasn't until around the turn of the century that corporate greed had taken its toll on the trains' appearances.