One reason the British sex comedy was never particularly well regarded by critics is, at base, social class: Middle class critics were looking at a working class form that drew more from music hall than modernist theatre and whose pleasures were thereby fundamentally alien to them.
Available to buy from Movie Poster Mem; another design is here http://www.wrongsideoftheart.com/2009/10/keep-it-up-jack-1973-uk/
The correlations are immediately made in this 1973 entry from Derek Ford in that it opens on a pier-front theatre where protagonist Jack James (Mark Jones) is performing his one-man version of Oliver Twist, then develops into a bawdier version of the Victorian-era farce Charley's Aunt.
All that's needed here is the Donald McGill postcard as well
Unfortunately for Jack times are not what they were and the theatre's owner soon decides that his act – which had been performed by his father and grandfather before him – is not what is needed to draw in the punters these days.
At this point Jack has a stroke of luck as he inherits a property following the death of his aunt. It turns out that the place is a brothel where she was the madam. Or, rather it was a brothel, seeing as only one of the girls working there, the ironically named Virginia (Sue Longhurst) remains on site.
Taking a fancy to Virginia, Jack starts posing as his aunt and re-opens the place for business.
He soon learns that Virginia has distinctly amorous intentions towards Auntie. But rather than coming clean about things (oo er!) Jack continues to keep it up (fnaar fnaar!) and impersonate all manner of the brothel's clients, each with their own preferences and pecadilloes amongst the seven women now working there...
The set up gives plenty scope for Jones and Longhurst to demonstrate their talents.
Jones’s various personas are particular highlight – even if his Japanese visitor is, inevitably, the kind of Mickey Rooney in Breakfast at Tiffany’s style caricature unacceptable today. Interestingly earlier in his career Jones had worked with avant garde theatre director Peter Brook, suggesting that just because something appealed to the critics this didn't necessarily mean it provided a decent wage for the actor.
Longhurst, meanwhile, comes across (oo er!) as something of a British version of Edwige Fenech: Sexy, uninhibited and a whole lot better actress than many would probably give her credit for.
Though the version I saw was strictly softcore Ford apparently also shot alternative hardcore scenes for the export market. As it is there are some scenes which push the envelope a bit, such as Longhurst's memorable first appearance, lying naked on a bed pleasuring herself, and a pseudo-lesbian threesome.
Sue Longhurst goes exploring
There are also some amusing in-jokes: One of the prostitutes, who specialises in playing an infantile role, is played by On the Buses's Linda Regan. When the place is threatened with closure she remarks that she may have to go back “on the buses”...