I stand corrected; this is the one that Million Dollar Nickels calls the "Hawn Specimen" (after it's most recent owner, Olsen owned it some time before that). Graded by PCGS as PF-64. King Farouk bought it in 1949 and was forced to abandon it (as well as the rest of his collection) when he had to flee Egypt after being deposed in 1952.
No worries! Ive been there a number of times already and I’m not going to pretend that it won’t be my last. From my understanding after just a quick search: Farouk actually had 2 of them at one point, one being resold and one now being housed at the Smithsonian.