Annette Bening great as Gloria Grahame in ‘Film Stars Don’t Die in Liverpool'

‘Film Stars Don’t Die in Liverpool” is based on a book of the same name, a memoir by Peter Turner about his love affair with the actress Gloria Grahame when he was an aspiring actor in his 20s and she was in her mid-50s.

But as the title suggests, Turner’s recollections aren’t about his unlikely but utterly affecting May-December romance; rather, he recounts how, at the end of her life, Grahame sought to reconnect with her then ex-lover, seeking refuge in his working-class home in Liverpool to be tended by his loving, unruly, often tartly amusing family.

As the movie version of “Film Stars Don’t Die in Liverpool” opens, we see the middle-aged Gloria, portrayed in a virtuosic performance by Annette Bening, in front of a dressing room mirror, putting on her face: From these first few moments, it’s clear that Matt Greenhalgh’s script won’t traffic in the artifice of Hollywood glamour, but rather the vulnerabilities at its tender, less photogenic core.

Soon, Gloria is fetching up at Peter’s house, where he is trying to convince his parents to visit one of his siblings in the Philippines. Rather than welcome the frail diva with abashed deference, the Turners take her in as they would any stray friend or relative - with a soft bed, hot tea and no intrusive questions.

Soon, Peter-played in a sensitive, appealing turn by Jamie Bell - is revisiting how he and Gloria met, and it’s in these transitions that director Paul McGuigan shines, shifting time frames with graceful ingenuity and musical echoes of then-vs.-now. Rather than a pathetic attempt at reclaiming her youth on the part of Gloria, or star-struck ambition on the part of Peter, their relationship is clearly revealed as a meeting of the minds, whether they’re dancing to pop songs or rehearsing lines from the play she’s doing on the outskirts of London. The simple pleasures of “Film Stars” lie in the sincerity with which it honors friendship, unapologetic attraction and deep loyalty, which, in another instance of McGuigan’s gift for shaping perspective, comes to play an ironic role in the couple’s demise.

The sweetness and simplicity of this love affair is so beguiling - and Bell and Bening bring such winsome, unvarnished idealism to their roles- that it’s tempting to be happy with what “Film Stars” does right. (In addition to the lead players, Julie Walters, Kenneth Cranham and Vanessa Redgrave are all terrific as various and sundry parents.) It’s only upon reflection that viewers may realize that, despite its nominal title character, the movie never delves that deeply into who Gloria Grahame was, aside from a femme fatale slinking across a black-and-white screen.

Bening lends her portrayal a fascinating mix of no-nonsense flint and tenderness. But she’s also kittenish where Grahame was sultry, whispery where Grahame was throaty and alluring. This might be closer to Grahame’s real-life persona than we realize, but audiences, especially those not familiar with “The Bad and the Beautiful” and “In a Lonely Place” should get more than just a fleeting hint of what Grahame meant to movie buffs in her heyday.

As a straightforward retelling of Turner’s own unfussy tale, “Film Stars Don’t Die in Liverpool” possesses the benefits of forthrightness, but that also lends it an air of banality: What is surely one of the unique love stories of its generation is robbed of its strange, even bizarre beauty. It’s a perfectly lovely little film, which is fine. But film fans can be forgiven for wanting more.