Anyone casually inferring that the title of this 90-minute documentary might shed light on the inner workings of knowing music-hall surrealist Frankie Howerd is likely to be mildly disappointed. The Lost Tapes is far more interested in his stage-and-screen career than his occasionally tumultuous private life. That said, the plethora of footage unearthed here is an absolute treat for any fan of British comedy. Bruce Forsyth, Tim Vine, Ross Noble, Roy Hudd, Galton & Simpson and the eternally youthful Barry Cryer guide us through clips ranging from Frankie's stint at Peter Cook's Establishment Club to his scenes - sadly left on the cutting-room floor - with Wendy Richard and Paul McCartney in The Beatles' Help! to footage of another musical misfire in his role opposite The Bee Gees in the regrettable promotional movie that accompanied their Cucumber Castle LP. Other nuggets include clips from 1973 Up Pompeii! rehash Whoops Baghdad and a 1976 sitcom made for Canadian TV.

He's part Betjeman, part Meldrew and part stand-up comic gunning for his audience. There can't be many Dr Henry Pickerskills alive and working now in the education system because his brand of tough love, rough justice and abrasive shafts of wit directed at his pupils would probably breach the Human Rights Act.

The Pickerskill Reports is back with more of Dr P's ironic stories of life long ago at a boys' boarding school whose ethos is one in which normal laws don't apply, let alone what would then have been fanciful libertarianism. Dr P arrives in his classroom like Dirty Harry. Nemesis of bullies, alleviator of the torment of those he calls his "spirited iconoclasts" and a complete enigma to his headmaster who, somewhere in the recesses of his brain, knows that his English teacher is running rings around him.

The head is portrayed as militaristic but feeble-minded by Mike Sarne, the actor and director who has covered much ground since he tried to persuade Wendy Richard to Come Outside in the 1962 pop song. Making a guest appearance in the first episode was Sheridan Smith, also showing her versatility as an aristocrat playing at gender politics. Ian McDiarmid, as Dr P, brings a dryness of delivery and impeccable timing to the role while clearly relishing Andrew McGibbon's sardonic and entertaining script.

While some comedians are lionised after they've stopped appearing on TV, others are quietly forgotten. Nicholas Parsons spends more than Just a Minute with Paul Merton recalling his partnership with one of the latter - Arthur Haynes. Viewers of a certain age will recall the partnership that pulled huge audiences to ITV in the 1950s and 60s. It's the comedy of a simpler, slower age; Parsons remembers how depicting a vicar in a sketch was considered disrespectful. There's nostalgia and curiosity value, not least with a priceless archive interview with writer Johnny Speight. Plus, rewarding glimpses of Wendy Richard, Patricia Hayes, Michael Caine and the Rolling Stones.

In tonight's double bill from 2008, vinegary gran Madge (Sheila Reid) meets her match in hard nut Sylvia - Wendy Richard in her first role after EastEnders. Their High Noon face-off around the pool in cowgirl hats and mobility scooters is a comedy classic. Meanwhile, the overweight swingers have managed to break a second bed at the Solana Resort, despite not "really going at it" and Jacqueline (saucy Janine Duvitski) keeping "one leg on the vanity unit". Benidorm benefits from a terrific ensemble, but tonight's second episode belongs to Siobhan Finneran - on another planet from her wicked soap-dropping O'Brien in Downton Abbey. As put-upon mum Janice, she's astonished by the advances of a randy Jack the lad, then stuns everyone by serenading oafish hubby Mick (Steve Pemberton) with Dead Ringer for Love at the karaoke. Like a post-watershed Corrie meets Carry On Abroad, Benidorm's hilarious sun-drenched bawdry is the perfect antidote to January blues.

"Before we go any further, Mr Rumbold, Miss Brahms and I would like to complain about the state of our drawers. They're a positive disgrace." This was about as sophisticated as Are You Being Served? got, yet it ran for 69 episodes from 1972 to 1985, becoming one of Britain's best-loved sitcoms. Despite its reliance on tame innuendo and catchphrases, it showcased impeccable comic acting from Wendy Richard and Mollie Sugden, who both died last year. The show also made a star of the late John Inman. His character, the mincing menswear fitter Mr Humphries, was criticised by gay rights groups, but Inman was later hailed as a gay icon (especially in San Francisco, after the series became a cult hit on US TV in the 1980s). This documentary tells the sitcom's story. It's preceded by profiles of Sugden and Inman, and 1975's Christmas special; afterwards there's a colourisation of the original black and white pilot episode. Wonder what colour they'll make Mrs Slocombe's... hair?

Wendy Richard speaking about her work on the 2nd series in her autobiography - Wendy Richard(no 's'): My Life Story:

Unfortunately, it was a nightmare to work on. Hylda may have been the top comedienne in the country but there were problems persuading her to rehearse and as a consequence - bless her heart - her lines were not coming easily. She claimed it was far too tiring for her to rehearse on studio day but as a result it meant the cameras could not line up correctly without her.

In order to circumvent the problems of the absent Miss Baker on studio day, what they did was employ someone to deputize for her. The difficulty was though that the stand-in was a young girl who was very tall. So they had to pin a photo of Hylda on the woman's chest at the exact height where Hylda's face should be and the poor cameraman had to line up on that!