Ask Sir John Mills about his tie and he nearly jumps out of his chair with delight.

"Good question!" he says, leaning dangerously close to a plate of bay scallops served up by the Sheraton Carlton, and making you feel it was an act of extraordinary discernment to notice the gold coat of arms over two brilliant red and white stripes on a navy-blue background.

"It's a very special tie," he says proudly. "There are very few about." The emblem, he explains, is that of the HMS Kelly, Lord Louis Mountbatten's destroyer, the ship memorialized in the 1942 film "In Which We Serve," with then just-plain-John Mills among the crew led by Captain (and author/director) Noel Coward. For his performance as Able Seaman Shorty Blake, Mills was made an honorary member of the ship's company, and he and his wife have been attending annual HMS Kelly reunion dinners ever since.

The tie is terribly dapper and impeccably right, like everything else about John Mills, from his neatly trimmed mustache to "Up in the Clouds, Gentlemen Please," the autobiography he has come to Washington to promote. ("Up in the Clouds" was a hit song in "The Five O'Clock Girl," the musical that gave Mills his first professional break in 1929. The call boy would knock on the door of the chorus dressing room and shout, "All down for 'Up in the Clouds' gentlemen, please.")

Mills and his wife of 40 years, author Mary Hayley Bell (whose middle name became the first name of their famous daughter), are on a four-week promotion tour of the States. At 73, he wears a hearing aid subtly built into the frame of his eyeglasses. Otherwise his energy is all self-generated, and all but boundless. A few days ago in New York, he did seven radio and TV appearances, arriving for "Good Morning America" at 6:30 a.m.

The book jacket describes him as "Britain's Best-Loved Actor," but he was a reluctant memoirist. Three years ago, at his 70th birthday party (attended by Lord Laurence Olivier and Sirs Alec Guinness, Ralph Richardson and John Gielgud, among other "masses of people I've worked with in my life"), Mills was talked into it by Pamela Harcourt, wife of Lord Harcourt, the press magnate. She told him he had simply known too many people and seen too many things to keep them to himself.

The book contains the mandatory minimum of vaguely off-color anecdotes -- like the time when, at 19, Mills and several other young British actors visited the "look-through room" of a Neapolitan brothel and observed a transaction involving, by chance, a fellow member of their troupe. "I don't think he ever reached that peak of perfection in any other part that he played during the tour," the author comments.

But even after the passage of half a century, he doesn't mention the actor's name. When he mentions a name, it is usually in a context of high praise and profuse gratitude.

Mills is no less grateful in person than in print. His career seems to have been one long series of lucky breaks, starting almost immediately after he made what his father called his "most unwise decision" to become an actor. Fresh from the chorus of "The Five O'Clock Girl," he went to audition for a touring production of "Journey's End," a now-forgotten play about British soldiers in World War I. He had come in hoping for the lead, but was asked to audition for a supporting part, rejected and sent on home. Unknown to Mills, however, the playwright had walked in on the tail end of this unsuccessful reading, and prevailed on the producer and director to summon the young actor back to read for the part he had wanted in the first place. Mills got the part, which meant joining a troupe called "The Quaints" that carried an ambitious repertory of modern plays, musical comedies and Shakespeare to India and the far reaches of Britain's Asiatic empire, in 1929 and '30.

"That was at the height of the Raj when the empire was still the empire," says Mills, looking rather imperial himself with a red kerchief flowing from the pocket of his blazer.

Logistics dictated a stripped-down approach to the Quaints' repertory. The Shakespeare was "absolutely appalling," Mills remembers, and at one matinee performance in India, they actually switched from "Hamlet" to "Julius Caesar" between acts, without telling the audience. The actor playing Horatio "wasn't fit to continue in the second act," Mills explains. The audiences for the evening performances were mainly British, but the matinees attracted a large contingent of Indian drama students, who made a great deal of noise that afternoon flipping through their texts in confusion.

The company did a better job with lighter more contemporary fare. So it was probably a fortunate thing for Mills' career that when Noel Coward passed through Singapore and chanced on a poster that promised "The Quaints in 'Hamlet'," it turned out to be a mistake. The play Coward actually saw that night, entitled "Mr. Cinders," was a comedy with Mills in the leading role. His entrance was made on roller skates, and it was more impressive than usual when Coward saw it, because the star skated in so eagerly that he did a complete somersault and landed on his back, getting a huge laugh.

Coward proceeded to adopt the Quaints as mascots, even performing with them when one of the regular cast fell ill. He asked Mills to call when the company came home. "For a young actor to get anywhere near Noel Coward was absolutely wonderful," says Mills.

Back in London, Mills rang up Coward and was invited to see "Private Lives," with a four-person cast consisting of the author, Gertrude Lawrence, Laurence Olivier and Adrienne Allen. "It was an evening of magic," he says 50 years later. He was soon cast in a series of Coward shows, including "Words and Music" and "Cavalcade."

Mills dubbed Coward "The Master," and Coward obliged by acting the part. He taught his protege to take bad reviews in stride, advising him to disregard the good ones too and to trust the judgment of a carefully chosen group of peers instead. Coward also convinced him to turn down a seven-year contract offer from 20th-Century Fox that went with the opportunity to repeat his "Cavalcade" role on film. In retrospect, Mills regards that decision as one of the soundest of his life. By continuing with his stage career, he believes he equipped himself to play an increasingly wide range of character roles in later life, culminating in the village idiot's part that won him an Oscar for the 1969 film "Ryan's Daughter."

After one early flot, "The 1931 Revue" (with several songs supplied by Coward), "I was very lucky," says Mills. "I went from one thing to another." In between stage assignments, he acted in "quota" films -- domestic productions that British cinemas were required to pair up with the more popular American imports. One of these, a lugubriously-paced epic called "Ghost Camera," was virtually jeered off the screen when it dared to share a double bill with an MGM release starring Clark Gable and Spencer Tracy. Sitting in that restive audience, Mills decided to avoid detection by joining in the general hooting and catcalling.

There were several bleak years in the mid-'30s, when he resolved to turn down all musicals and hold out for a straight play. Then, through Olivier's intervention, Tyrone Guthrie offered Mills a season with the Old Vic, playing Puck in "A Midsummer Night's Dream" and Young Marlowe in "She Stoops to Conquer." This was followed by the role of George in John Steibeck's "Of Mice and Men," for which he prepared by watching James Cagney in "Angels With Dirty Faces" at least 12 times.

Then "Mr. Hitler" intervened, and Mills spent a year and a half in the Royal Engineers, until disqualified by an ulcer. He never went back to the Old Vic, and so, he says with a sly smile, "Nobody will ever know that I would have been much better than Olivier in all those parts."

In January 1941, having extricated himself from an unhappy first marriage, Lt. J. Mills married his present wife. They had met 12 years earlier in Tsientsin, China, when the Quaints were invited to tea and tennis by her father, Colonel Hayley Bel, a British customs official who kept watch on smugglers, gunrunners and pirates in the area.

With her husband's encouragement, Mary Hayley Bell turned from acting to playwriting in the '40s, and they enjoyed several joint successes as author and director/star, respectively. In one, "Duet for Two Hands," as author Mills played a pianist who lost his hands in an accident and had a murderer's hands grafted on in their place (the premise has also served several horror movies). The Mills team had its failures too, including a play called "The Uninvited Guest" that provoked one critic to say: "And John Mills wanders about the stage in a red wig looking like a bewildered carrot."

His film career got rolling just when the British film industry did. Along with the Coward productions "In Which We Serve, and "This Happy Breed," there were supporting roles in "Cottage to Let," "The Young Mr. Pitt," "We Dive at Dawn" and "Waterloo Road." Then came the chance to play Pip in David Lean's adaptation of "Great Expectations," with Alec Guinness as Pocket. It was Guinness's first film and Mills remembers him as "sickly and fright."

The list of Mills' former co-workers and close friends includes not only Guinness, Coward, Gielgud and Richardson, but Robert Donat, Joan Greenwood, Alistair Sim, Robert Newton, Trevor Howard, Harry Andrews, Cedric Hardwicke, Charles Laughton and innumerable others. He was in the midst of an extraordinary flowering of acting talent that won't happen again anytime soon.

"One of the penalties of my age," he writes, "is that so many of my friends have decided that they have done enough entertaining down here and have taken off and are, I hope, playing to packed houses upstairs." He quotes Coward on the same subject: "I do know what you mean, dear boy. When I have lunch with anyone these days I consider myself fortunate if he lasts till the coffee."

The repertory system and the institution of touring are the only explanations Mills can offer for why so many memorable British actors came to maturity in the years between the wars. He blames TV for the fact that so many current actors can't even make themselves heard, and he laments the current preoccupation with "filthy language" and "taking their clothes off." Coward used to describe the theater as "a place of entertainment," Mills recalls "and I think that's what's missing nowadays.

He remembers Laughton, with whom he co-starred in "Hobson's Choice," as "very strange." "I've never acted with anybody like Charlie Laughton. He was like the most brilliant amateur I've ever seen." He worked with Olivier only once, and it was with Olivier the director rather than the actor, in a play that toured the provinces but never made it to London. Olivier had mapped out the staging like "a chart for D-Day," says Mills in a rare moment of gentle criticism. "I felt it was a little bit restricting."

In 1958, his career and family life became entangled when director J. Lee Thompson, visiting Mills to discuss an upcoming film called "Tiger Bay," was so taken with 12-year-old Hayley Mills that he cast her in the picture -- although she had never acted professionally and her part had been written for a boy. The next spring her father was writing in his diary: "Hayley's press quite amazing. Never seen better for any young actor. Hayley unimpressed. Her only concern is for the new chicks just hatched out at farm."

A decade later, after Walt Disney had helped make Hayley a worldwide star (Yokohama Airport was a sea of banners when she landed), she decided to marry producer Roy Boulting, who was twice her age. There is pain in Mills' voice as he dredges up that episode. "I think she was really a very fine actress," he says, " not just a little kid you put before the camera . . . I think Hayley really suffered with the marriage because he didn't really want her to act. The bridging period never happened. She never bridged. So that was really not our fault. We couldn't stop her marrying him. She had come of age."

In his attempts to dissuade her, however, Mills says he told his daughter that sooner or later she would fall in love with someone closer to her own age -- which is just what happened a few years ago when she did a play with actor Leigh Lawson (who plays Alec in the movie "Tess"). Now divorced and back working. Hayley Mills has just finished a British TV series about colonial Kenya at the turn of the century. "I think her career's just starting to recover," says her father. His other actress-daughter, Juliet, enjoyed a success on American TV in "Nanny and the Professor," and lived in Beverly Hills.

The elder Mills is still working -- more on stage (in Britain and Canada) than in films lately. A decade has passed since a run of strong movie parts (in "King Rat," "The Wrong Box," "The Family Way," "On What a Lovely War!" etc.) The problem is "the demise of the film industry," says Mills wistfully. But he pronounces it "de-meez," and that makes it sound all right.