SMALL, sparkling and immaculately turned out, there’s still something of the film star about Margaret Barton.

Not the modern film star, you understand, with their entourages and their diva-ish ways, but a British film star of the black and white era. And a big one at that.

Margaret may be better known as Mrs James of Wimborne these days, trustee of the music charity set up with her husband Raymond in memory of their son, Michael. But for one night only on April 8 she’ll be gracing the town’s Tivoli Theatre for a gala screening of her most famous film: Brief Encounter.

“I am very excited,” she says, in a voice as clear and crisp as new-fallen snow. That voice is nothing like the one she employed 60 years ago as Beryl, the put-upon junior tea-girl in Brief Encounter, but Margaret is nothing if not a fine actress.

So good, in fact, that far from having to audition for her most famous part, she was picked out by the film’s director David Lean and by its writer, Noel Coward, who had seen her performing in the West End.

“It was very flattering indeed because it was my first film.”

Exciting enough, then, but what no one could possibly have foreseen was that this little film about unrequited middle-class love in a suburban town, which mainly takes place at a train-station tea-room, would become a cult classic, still being screened worldwide, and now just about to be released on Blu-Ray.

“Nobody had any idea of what it would become,” says Margaret. “David Lean would have been utterly surprised. I think he thought it was a nice little film to put into the schedules and he wasn’t going to think about it too much. But he worked on it very hard and was a lovely director.”

On set at Denham film studios, where she was chauffeured each day, Lean took Margaret under his wing.

“I was only 18 and he used to ask me down on the set, just to see what Celia Johnson and Trevor Howard (the actors playing the main characters) were going to do in a little bit of scene that he was directing.”

Because of this Margaret had a ring-seat view at the making of cinematic history. She was able to observe the acting skills of Celia Johnson, who plays bored housewife Laura Jesson, and who was nominated for an Oscar for her performance.

“She was a lovely person and I worked with her again in later years,” she says.

Another firm favourite on the set was Stanley Holloway, who played the station master. “Waiting for them to set up the next scene with the lighting and sound could be boring but Stanley used to go through some of his recitations to keep us amused,” she says.

Why does she think the film remains so popular?

“It’s partly to do with the music they used, the Rachmani-nov concerto Number 2. That piece was David Lean’s idea and it just fits like a hand in a glove.”

Margaret also believes the steam trains with their mournful whistles were another element that cemented the film in the public consciousness. “People love the nostalgic setting of the railway station.”

And, of course, the film was shot in atmospheric black and white, with lighting that Margaret says took ‘hours’ to create.

As the sole surviving member of the principal cast – she was seventh on the bill – Margaret has found herself as keeper of the Brief Encounter flame.

“I still get letters from all over the world; America, Australia, Italy, there’s even a Friends of Brief Encounter.”

What do they most want to know?

“Mainly they ask ‘would they be able to remake it now’ and I usually say no, I’m afraid not, because I think they would have been in bed together the first time they met!

“It’s that sort of nostalgic feeling for the past that I think people love.”

After losing their only son, Michael, to cancer when he was just 31, she and husband Ray-mond, a former Prof-essor at the Guildhall School of Music and Drama, have built a fabulous memorial to him in the shape of the Michael James Music Trust.

“We support young people to get through their training and become especially good musicians as Michael was,” says Margaret. “He was a former assistant organist at the Minster and an organ scholar at Durham University.”

It was because of Michael that Margaret abandoned her acting career. “I did carry on when he was a baby but after a while realised he needed me at home.”

Now Margaret works for the trust and as a public speaker. Naturally, there is one topic that everyone wants to hear about.

“I know it sounds funny because it was so long ago but in a way I am still working for Brief Encounter,” she smiles.

The film will be shown at the Tivoli in Wimborne on April 8 at 7.30pm. To book a seat, call 01202 885566.