This chapter and the mention of England made me hope there'd be cameos from Emma Victorian Romance(author's earlier work) toward the end of this series, but checking some earlier chapters had my hopes dashed.
Crimean War went on 1853-1856 and by this time in the story hostilities are only just starting to brew up. That places this story somewhat square in the middle of the 19th century, sometime around 1850. Also, that would corroborate the appearance of Smith's friend in Ankara, Mr Hawkins, if he's based on the real historical figure of architect Major Rohde Hawkins who was studying in Ankara at that point in time.
Emma, on the hand, take place at the very end of the century so there'd be major time-gap between the stories and characters. If this was the author's older work it might have worked, but as it is I doubt we'll see any cameos in this...