A casserole of period nostalgia awash in sentimentality sauce and festooned with calculated cliches, “Mrs. Henderson Presents” is a strange picture indeed to come from Stephen Frears, a director who usually serves up sterner fare. It shares with last year’s “Being Julia” a colorful theatrical background, an air of genteel naughtiness and a prima donna star turn, this time from Judi Dench rather than Annette Bening. And it will appeal almost exclusively to the same audience that found the earlier film so winning–older women. Indeed, one can imagine it effortlessly capturing the affections of the larger gender group in the nursing home crowd. Men of a certain age and temperament might be susceptible, too. But younger audiences will find it little more than a musty museum piece–a Masterpiece Theatre episode with a little skin added for the paying customers (much as in the plot, too).

Based, as almost everything seems to be nowadays, on a “true story” (though undoubtedly very loosely indeed), the movie centers on the titular widow (Dench), a rich aristocrat of the 1930s who tires of the sedate life of a social gadfly and decides to use her wealth to reopen a long-shuttered West End theatre as a site for musical revues. Enthusiastic (and predictably acerbic of tongue and haughty of manner) but unknowledgeable in the business, she hires an experienced impresario, Vivian Van Damm (Bob Hoskins) to operate the venue. Naturally he’s a quite different person from those of her social class–business-minded and practical–but in his own way he’s as self-confident and demanding as she is, and the pairing is carefully drawn to allow for mildly comic clashes between them. Of course it’s an obligatory plot turn that though they’re very unlike, they eventually grow not only to respect one another but to feel a real mutual affection, too.

On the broader historical canvas, however, the movie emphasizes three larger plot elements. One is the initial setting up of the theatre in terms of its programming–a revolutionary decision to have its musical revue play continuously, rather than have only two shows a day (though how the cast could sustain such a schedule is never explained)–and assembling the performers not from the ranks of “established” stars–with the exception of headliner Bertie (Will Young), a singer-and-hoofer whom Van Damm hires away from another house) but by going into the hinterlands to find new, particularly female, talent–most notably a beautiful blonde named Maureen (Kelly Reilly), who becomes the linchpin of the chorus. The second involves Mrs. Henderson’s notion, when the initially strong boxoffice receipts decline as other theatres copy their recipe for success, to add some discreet nudity to the shows to entice audiences back. And the third centers on the effort to keep the theatre open during the German bombing of London during World War II (the fact that it’s actually located underground being of importance in that regard). The decisions on the latter two points involve Mrs. Henderson’s handling of the Lord Chamberlain (and therefore chief censor) of the realm, Lord Cromer (Christopher Guest), whom she proves able to manipulate with a combination of skill and simple aggression.

As if all that weren’t enough, “Mrs. Henderson Presents” adds further complications to the scenario–the widow’s sad family past, which helps to explain her commitment not just to the theatre but to its “naughty” nude tableaux (the Chancellor will allow only static, “artistic” poses, you see); her effort to set Kelly up with a young soldier just going off to war, which turns out badly; and a strange episode in which she’s infuriated by the revelation that Van Damm is married, and absents herself from the theatre, only to try to regain admittance in a series of weird disguises. Most of these addenda don’t work particularly well, and tend to weigh down a narrative line that’s already a mite overloaded with schmaltz and period affectation.

Still, it’s sporadically enjoyable to see the cast strut their stuff, even when the material they’re asked to carry seems cumbersome. Dench obviously has a field day playing the haughty but lovable Henderson, and Hoskins–though condemned to sport slicked-down hair that looks painted on–has the gruff act down pat. (He is compelled to go au naturel briefly at one point, but Frears keeps him in discreet shadow, so that one needn’t worry about a Harvey Keitel moment.) Young, the winner of the British version of “American Idol,” shows real musical-hall talent of a sort conspicuously lacking in U.S. victors on the show (although overall the musical numbers aren’t staged with much imagination), while Guest makes the Chamberlain a deliciously malleable sort. Reilly, though, exhibits a rather glacial stiffness that turns Maureen into less an endearing figure than a distant one. Visually the picture manages to convey the feel of the period reasonably well, with Sandy Powell’s colorful costumes trumping the sometimes constricted feel of Hugo Luczyc-Wyhowski’s production design and Tony Woollard’s art direction, but George Fenton’s musical score is entirely pedestrian, keeping the movie earthbound when it should be trying to take flight.

All in all, “Mrs. Henderson Presents,” despite some really feeble plot turns, will go down easily enough with older audiences on the basis of its strong lead performances, its hints of harmless naughtiness and its appeals to sentiment. But one’s left with the feeling that Frears, Dench and Hoskins are coasting here in a film whose occasional modest pleasures evaporate even before the final credits begin to roll.