I know about Sphinx Tours. I went on one of their Eqypt tours 19 years ago.
The owner, Muhammed Husni, was a friend and customer of Jeff Lindsay (John Huxley).

Sphinx Tours was set up in 1966.
Below is a page from Who's Who with all the info.
I got an ashtray like that when I went on the tour but it still had the LA location on it as the Paris office hadn't even opened. Cairo came later still. Sorry, but the ashtray is modern.

Also below is an inlay from a Ewing mold order supplied by Huxley to the hotel Husni was affiliated with back in 1969 - The Sheraton. Huxley records indicate the El Salamlek in Alexandria had their first chip order in 1980.

I agree the C&S are 100% Burt and they exist on both square edge and round edge molds. So they could not possibly have been made before 1947 and the round edge ones place them before the end of the 1950's. Also, as sole distributor for Burt Co in Africa, Huxley would have had to have supplied any such chips. They did not or I would have had them in the Huxley collection which was complete.

I'm not 100% the C&S are from LA but they can't be in any way related to your ashtray. Just looks like someone liked collecting Sphinxes.
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