Sefi edited the
Philatelic Journal of Great Britain from 1926, and also
Philatelic World and
The West-End Philatelist. He researched the silk thread issues of Switzerland 1854-62. In
philatelic literature, his
magnum opus was his masterful "
An Introduction to Advanced Philately...", re-issued in facsimile form by the
Royal Philatelic Society London in 2010. At the time of his death, he was engaged with C.H. Mortimer in preparing a book on Jammu-Kashmir which was eventually published in 1937. He won the
Bates Prize at the 1923
Philatelic Congress of Great Britain in London, and the
Congress Cup for his paper "Forgeries and Fakes" at the 1929 Birmingham Congress. His philatelic interests were wide and he contributed numerous articles to philatelic periodicals. ==Other==