NEW YORK THEY wouldn't be the same Herman's Hermits without their leader. But Herman (Peter Noone) is forging a career of his own as an actor when he isn't singing rock 'n' roll. He appeared recently on ABC-TV's "Stage 67" show, "The Canterville Ghost," and hopes for other acting assignments.     Noone is a limp boned, quiet young man who appears appallingly rude at first meeting until he gets interested in what he is being asked.     His full name is Peter Blair Denis Bernard Noone, and he took the name Herman in a mistaken imitation of Sherman of the "Bullwinkle" cartoon series, whom he is supposed to resemble. His voice is pure Manchester, delightful in song but startling as a duke's on the ABC show.     Without destroying the proofreader's sanity, suffice it to say that "love" is "luv," don't is "doan't." "I" is "ah," and it comes out like, "Ah doan't worry abaht my accent. Ah used another one in Canterville an overdun, tingy thingy accent."     Peter was an actor before he became a rock 'n' roller, and he was slightly nettled when people were startled by his recent appearance in "Canterville Ghost."     "I've always acted," he said. "I was a little nervous, I suppose. Joe Wishy, the executive producer, came to Houston and asked if I wanted to do it and I said I'd think about it. When I found out who else was in it, I wanted to do it and it was also a challenge - to bring in another age group, y'know - I want to do more of that when I'm ready."     Then suddenly the rude young man looks very young and very honest. "I felt stupid playing the part; that's why I wanted to do it. It's not really me, it really is acting. I usually act daft things, y'know, act the fool. I always have a laugh.     "And I wanted to do it because of Michael

Redgrave. He's so serious. And he taught me a lesson. Lines like 'I luv you. I luv you'; I crack up with lines like that, but he taught me to just say them straight. He's so professional."     Peter was in New York in the middle of a tour of this country, and he has definite views about the United States.     "Y'know, you've got a bad image abroad," he said. "Everybody thinks the States is like Confidental magazine, and all the fan magazines and all. And Americans are so rude abroad.     "For instance," he said, stretching his long legs under the table and shifting his weight slightly from the end of his spine where it had been sitting for 20 minutes,"in Europe in a restaurant you get slow service maybe. But the food is apt to be better, while here you get it fast, but it's bloody awful.     "I don't like food in England or America, really. The only food I like is home food. But I must say," he added with a small smile, "I had the most marvellous steak for lunch; and then you always have, you know, grass. Lettuce; you know, salad.     "I like to cook," he added, surprisingly. "I'll never forget the first meal I ever cooked. I won a cockerel at a party and I stuck it in a pressure cooker and I screwed it all down and the whole bloody thing exploded all over the ceiling. Wot a mess!"     Peter doesn't give the impression of being very close to the members of his troupe, more than as good working companions. But he does know the inside talk of the rock 'n' roll singers. He also has a responsible attitude toward his fans.     "People in the different singing groups nod at each other and we know each other, but we wouldn't be on the same show together. What producer would want to anyway? In any case, I'd rather go home and listen to my old records than sit about listening to someone else sing," he said.     When asked about the celebrated remark of John Lennon of the Beatles to the effect that rock 'n' roll was more popular than Jesus, Noone thought for a few moments and then said, "I don't think he should have said it. He knows he shouldn't have said it. He feels very badly about it. But then, all the last few years I have carefully avoided discussing religion or politics. I think it's a personal thing, and it could be upsetting to his fans. It's not fair to get involved with that if your fans may be religious.     He paused, and then said with a wide smile, "Have you ever heard of a place called Padookah, Kentooky? Isn't that grand?"