Japanese artifacts would have been rarities in Regency England, because until the 1850s, Japan was almost completely closed to Western trade. But through Dejima, an outpost in the port of Nagasaki, Dutch merchants—such as those in Lady Beatrix’s background—were permitted to trade with the Japanese on a closely monitored basis.
In reality, the type of Japanese puzzle box that plays such a significant role in this story—the himitsu-bako (“secret box”)—didn’t develop as an art form until about a century after Lady Beatrix’s puzzle box made its way westward. But certainly a gifted artisan could have made a puzzle box in an earlier year. Historical romance characters often benefit from the possible, which gives much more scope for storytelling than the likely or the everyday.
A few medical notes: The term arthritis has been in use for joint pain since the 1500s, though it’s not likely a Regency physician would have been able to distinguish between different types. Lady Beatrix and her sister, Lady Fontaine, suffered from rheumatoid arthritis, an autoimmune disease that can strike at any age. Giles fears he has inherited that tendency, but his own pain is due to something many computer users are familiar with: carpal tunnel syndrome. The symptoms can mimic those of arthritis, but unlike his mother, Giles would have been able to make a complete recovery with rest and care.
On a more festive note, Regency Christmases were simple compared to the elaborate celebrations of the Victorian era (not to mention today). The tradition of Christmas trees hadn’t yet begun, but perennial favorites such as mistletoe, puddings, evergreen garlands, and carols were all part of the holiday observances at the time. “Here We Come A-Wassailing” didn’t appear in print until the mid-1800s, but is thought to be centuries older. Holroyd’s Collection of Yorkshire Ballads (1892) dates the carol to the late Middle Ages and states that the lyrics “differ in almost every village in Yorkshire.” Naturally, characters in a historical romance would favor lyrics about love and joy.