So why is it that stamps of the Independent Kingdom (after 1922) have FR and French text on them? Was it just a diplomatic choice.
This is just speculation on my part, as I have not done any research to back my assertion ...
I know the French had a very strong presence in North Africa. I believe it started in the late 18th century with Napoleon Bonaparte when he went into Egypt to "Protect French trade routes". Some 30 years later, in 1831, the French foreign legion was created and their first task was the colonization of Algiers (Algeria). The french had a presence in Algeria until after WWII.
From 1831 until well into the 20th century, France tried expanding their influence over the region through colonization.
This is where the speculation part comes in ...
Being that France had such a strong presence in North Africa, both militarily and economically. And the liklihood that there were members of the foreign legion who were native to North Africa, it would make sense that French currency became the preferred currency of the entire region.
Thus, you have your answer. Egypt used French currency after independence because it was widely available and accepted throughout the region.
Is the line I have drawn a little thin? Perhaps ... but I like to think outside the box :)