So I think I've got the last three 1840 stories in place.
The Feast of Atonement, Constantinople, October 1840: Sabbateans, the Ahrida Synagogue, the Tanzimat, and intrigues involving Central Asian emigres;
The Day of Joining, Beit Mina and Tiberias, December 1840: Eid al-Banat, a by-election...