I'm completely at a loss with this. There's literally not a single thing on this stamp that can help me. Can't find it under Persia or the Ottoman Empire, and honestly don't have a clue where to search next. Early Egypt? Some other Arabian state?
I think you're on to something there. Don't have a catalogue that has Nejd, Hejaz or Saudi Arabia in it, but a quick Google search on Nejd stamps gave me some images that look a lot like my stamp. Worth checking out. Thanks Edwin.
Ronald Storrs, who was later Military Governor of Jerusalem, was deeply involved with these stamps. In his autobiography Orientations he makes a few references to Lawrence and the stamps. Unfortunately, his index only lists names, not subjects, so it's hard to track down the full story, but here are a couple of bits:
"... I must confess, almost with shame, that my sentiments in applying for him (Lawrence) were mainly gratitude for his assistance in the Hejaz stamp issue and in other matters, the high value I attached to his judgment on any question, and his admirable company. ..."
and from Storrs' journal for the 15.x.16 "... Prepared an informatory and propagandist list for distribution from Jeddah of new Hejaz stamp issue. ..."
Storrs was later Governor of Cyprus at the time of the 1928 50th Anniversary of British Rule set, and was heavily involved in the design of the stamps.