Found in Words Etc.,: A Miscellany (Wordspress, Haslemere 1973) this piece by author, art teacher, botanist and curator Wilfrid Jasper Walter Blunt (1901 - 1987). His meeting with Hitler is admittedly fleeting, his meeting with Pavlova slightly  more substantial, but he tells both anecdotes well..

My Friendships with the Famous

Name-dropping is a pleasant and a fairly innocuous pastime, indulged in even by Shakespeare's Hipolyta: "I was with Hercules and Cadmus once…". At a party, when conversation is flagging, I sometimes like to electrify the company by saying, quite casually, "The first time I met Hitler was…". Then, before I can be subjected to an embarrassing interrogation, I change the subject.

No publisher has ever shown the slightest eagerness to publish a full-length book on my relationship with the Führer; yet I feel that the world ought no longer to be deprived of some account of my first (and alas! last) unforgettable meeting with him. I cannot, unfortunately, remember the exact date but it was some time in the year 1929. I had gone with a German friend to the Café Hecht, in the Hofgarten in Munich; Hecht means "pike", but little did I guess how big a fish I was about to land. At the table next to ours six people were sitting - three men and three women - and on that table was a funny little flag with a swastika on it; I assumed that they were adherents of some esoteric oriental religious cult. The men were dressed in brown (like our Capuchins), and one of them sported a ridiculous little moustache.