This is the sixth and final volume of the second edition of the set of David Levi Machzorim, as revised by Isaac Levy. At the end, it includes the long and interesting subscription list of those who paid in advance for copies of the book, with their names and addresses. The prayer for the king is, of course, for King George the Third. My copy has its original red leather, gold blocked binding, and a book label saying that it belonged to Miss Hort.
Miss Hort was probably a member of the family of Abraham Hort. He was well known among London Jewry as a philanthropist and had filled the highest positions in the Great Synagogue at Duke’s Place. He served upon many charitable boards. His son Abraham Hort junior had settled in New Zealand. Chief Rabbi Solomon Hershell gave Abraham Hort senior written authority to establish a Jewish congregation in Wellington and “to promote Judaism in whatever way he thought fit”. 
Hort travelled to New Zealand in 1843 and conducted the first Jewish synagogue service held in New Zealand. He returned to London in 1859 and died there on 18th October 1869.
The book has several title pages, including an ornate engraved one. I have scanned these together with the first page with Hebrew and English, the prayer for the King and the subscription list, which is an important historical document listing mainly the principal families of the Ashkenazi Jewish community of London in 1807:
Jewish Miscellanies 
One thought on “Machzor leChag Hashavuos – The Form of Prayers for the Feast of Pentecost, London, 1807”