PASADENA, Calif. — It isn’t every actress who can repeat the role that made her famous 40 years ago. But Jean Marsh can.

Marsh is the British actress who played the plucky parlor maid, Rose, in the original PBS classic “Upstairs Downstairs,” a series she co-created with fellow thespian Dame Eileen Atkins.

When the three-part sequel arrives on “Masterpiece Classic” April 10, Marsh will be back in Rose’s starched apron, but this time at the top of the stairs as housekeeper.

“It’s the longest part I’ve played, five years of playing a part. You get to know somebody tremendously,” said Marsh.

“All the work that Eileen and I did, doing a treatment and thinking about it … I got to know Rose very well before we even started. And then I put her on like a coat, as if the coat was woven on me.”

But Marsh was uneasy returning to the role. “She was a human being. She was delightful, but she wasn’t particularly like me. I’m not a great respecter of authority. I admired her tremendously. But it was very odd putting that coat on again. It was emotional because I was putting on the past. The past is a foreign country, you don’t always want to go there. I loved doing it, and I loved it being over and having the freedom of going on with other work.”

Playing Rose this time was more intense, she thinks. The show was filmed in Cardiff, far from Marsh’s London flat. “Going back was hard because of thinking about the people who are now dead, the downstairs people,” she said.

“Gordon (Jackson), really more than anybody because he went on being a friend forever. And thinking about dear Angela (Baddeley) and she was younger than I am now when she died … Lots of things were good about it, but from time to time in the kitchen I’d become choked up.

“I think I became more Rose with this than I was the first time. I was almost confused. I probably did become more because I was so isolated. I was living alone, working in a way we’d not done it before. So being a little isolated, Rose was more like real life than Jean was.”

In spite of her excellent performance, Marsh never played a maid again. She did Shakespeare with John Gielgud, “Twilight Zone” with Rod Serling, the sitcom “9 to 5” with Rita Moreno, but never another domestic.

In fact, she left the original show early. “They recorded it out of order because they wanted me to be in the last show. I was going to New York to do a play of Alan Bennett’s and I was doing a part totally different to Rose. And after that I played a South African spy in ‘The Eagle has Landed,’ did ‘9 to 5’ playing the bitchy office woman, then ‘Pygmalion’ in the theater. I’ve never played a part since that was remotely like Rose. So I was very lucky.”

Like Rose, Marsh has spent most of her life single. She married actor Jon Pertwee briefly when she was very young. “It didn’t last, a year and a half or something,” she said. “I ran away. I went to New York and lived there for about three years. I wasn’t frightened of New York, I had a boyfriend there. He was an actor, too. My dalliances have stayed in the business.

“ … It’s who you meet. The life of an actor would drive somebody who’s not in the business crazy, but a fellow actor understands it. People do marry within their professions quite often.”

Marsh grew up in a working-class family. Her father was a laborer in the print business. “Mummy had been a maid, but in a very big pub hotel, a sort of maid-of-all-work. Then she became a barmaid. That sounds odd today, but it was going up in the world. She was a barmaid as long as I can remember. Maybe during the war she might have done something else, I don’t remember,” she said.

“But when my sister and I started working as kids, she chaperoned us and she was so good at it that she became an official chaperone. You have to have those. They (child actors) can’t wander around on their own and mommies and daddies aren’t always available. So it’s a profession and you have to be licensed in England for it.”

Those early years as part breadwinner for her family have made her strong. “I used to be frightened of dying poor and having to put shillings in the gas meter, that sort of thing. But I think now that I’m safe because I can downsize easily and be quite happy.”

For those who missed the original, a special 40th anniversary edition of all five seasons is now available on DVD.

‘Upstairs Downstairs’

‘Upstairs Downstairs’

When: 9 p.m. April 10

Where: PBS

When: 9 p.m. April 10

Where: PBS