May 2013 I reported Brit entertainer Jessica Walker’s about-to-be NY debut would include letters Prince Philip long ago sent to the ’40s and ’50s musical star Pat Kirkwood. Back again, Walker’s one-woman musical “Pat Kirkwood Is Angry” will include the private mail between HRH and Kirkwood, rumors about the two have swirled for decades.

Today is Prince Philip’s 93rd birthday. The Queen’s throwing a Buckingham Palace Garden Party in his honor. A not terrific present is news that Jessica’s new show about Kirkwood opens today at our 59 E59 Theater.

The letters, written from Sandringham and Balmoral, exist in possession of Britain’s royal biographer Michael Thornton. Kirkwood’s will instructs beneficiary Thornton hand them to His Royal Highness’ official biographer after Philip’s death.

Defending use of the correspondence, Walker calls it “important” history. “What could’ve seemed Pat’s paranoid imaginings turns into proof.”

Happy Birthday Phil.

Odds & ends

Tilda Swinton in beige raincoat leaving the Met . . . Alfred Molina filming new series “Matador” for El Rey. What’s El Rey? “A new DirecTV network.” What’s “Matador”? “Not about bullfighting. I play a CIA agent.” And if you can understand that you’re a better man than I am, Gunga Din . . . May brings the hardcover “Ain’t It Time We Said Goodbye: The Rolling Stones on the Road to Exile.” Oy. Author, Robert Greenfield.

Dads & moms

Chris Christie, getting some Father of the Year award, called our wee metropolis “that other place across the tunnel.” Tunnel. Never mentioned we also hang off the other side of his George Washington Bridge . . . Best Mother awardee Norah O’Donnell was asked by 7-year-old son Kevin if that means Best Mother in the Whole United States. Replied Norah: “Well . . . yes . . .”

Nathan’s dishes dogs

Wayne Norbitz, Nathan’s Famous COO: “1916 the original Nathan, peeling and washing Feltman’s restaurant potatoes, befriended by co-workers Jimmy Durante and Eddie Cantor, borrowed $300 from a piano player and singing waiter, and opened a Coney Island stand.

“He hired actors as white-coated doctors to say hot dogs were healthy and charged only a nickel.

“Since 1916 nothing’s changed in the recipe. Fresh not frozen. Potted meats, best part of the cow, same spices Ida gave her husband Nathan. Frankfurt, Germany’s ‘Frankfurter’ then became ‘red hots.’ A New York Post cartoonist likened them to a long skinny dachshund but couldn’t spell that so he labelled them hot dogs.”

Grilled, boiled, broiled, fried, steamed, baked, microwaved, chili, mustard, relish, ketchup, mayonnaise, sauerkraut, onion, cheese, with the roll, without the roll, over a year 7-Eleven sells 100 million.

“In Yalta, Roosevelt sent them to Churchill and Stalin. For a party, Streisand shipped them to Europe. Young people, equally crazed, talk thin but eat fat. New Yorkers go everywhere. Starting here, it spread coast to coast. Yankee Stadium and Citi Field it’s the food of choice.

“Everybody loves hot dogs. July Fourth, our biggest day, we sell over 40,000.”

It’s next month. Ready the bicarb.

Fourth of July dreamin’

Debbie Harry on big holidays like July Fourth: “Families drive me nuts. Once I just took off and went to Mumbai” . . . Ryan O’Neal: “Same. I’ll never forget when I was little they decorated a Christmas tree. In a haunted house.”

Patron at “Casa Valentina”: “My mom was a chorus girl in Vegas. My father, too.”

Only in New York, kids, only in New York.