The elderly Mr. Feathersmith's bald head is an obvious wig/cap.
When the bell-tower strikes 12 midnight, a relatively light sky is visible.
When Mr. Feathersmith goes back to 1910 and visits the daughter of the banker he is making the deal with, the daughter plays a song on her piano. The piano she is playing is a New York-made Steinway Model B. However, the piano she is playing is a modern Steinway (1963) and not from the 1910 era from which it is supposed to be. This can be ascertained by the Sheraton arms of the piano framing the keyboard, which have squared off edges. In 1910, Steinway still used rounded arms framing the keyboard and it was not until many years later that the Sheraton arms were used (and are still used today).
While berating Mr. Deidrich, Mr. Feathersmith repeatedly alternates between the name-pronunciations "Dee-trick" and "Dee-tritch".