And now for something completely similar... the original Monty Python

Episode of lost comedy classic to be screened again, despite being wiped in the 1970s

With its scenes of cross-dressing, screeching old "women" and four Yorkshiremen regaling each other with tales of childhood poverty, it bears all the hallmarks of Monty Python's Flying Circus. Now, 36 years after it was last shown on British television, the BBC is to screen an episode of the series that spawned the Pythons - having pieced it together from grainy clips salvaged in a global archive search.

The newly restored instalment of At Last the 1948 Show is one of the most significant finds in the decades-long trawl for lost programmes provoked by the BBC and ITV's mass junking of archive material in the 1970s.

Credited with pioneering the meandering satirical sketches that were to become Monty Python's trademark, it was the first series to bring together the architects of that show, John Cleese and the late Graham Chapman.

It also inspired some of the Pythons' most enduring sketches, notably the "Four Yorkshiremen" routine that was one of the highlights of their live performances. The popular set-piece featured Chapman, Michael Palin, Terry Jones and Eric Idle as flat-cap-wearing northerners who try to outdo each other with their tales of childhood hardship and abuse.

Tim Brooke-Taylor, who, with the late Marty Feldman, made up the third and fourth Yorkshiremen in the original At Last the 1948 Show sketch, has welcomed news of the episode's rediscovery. However, he confessed to being annoyed that his absence from the Python line-up meant he never received the credit he deserved for helping to devise the moaning northerners.

"I've always been slightly irritated that, over the years, I never got any credit for the Four Yorkshiremen," he said. "It's very irritating. Everyone talks about the Pythons when it comes to that sketch, but they never actually did it on TV. Graham asked me if they could use it one day, and they did it at the Hollywood Bowl, but ever since people have associated it with them."

The "rediscovered" episode has been made fit for broadcast by the British Film Institute following an extraordinary restoration process achieved through a mix of tenacity, technical expertise and sheer serendipity.

It began when a private collector contacted the BFI to offer it an audio copy of an episode of At Last the 1948 Show that he had recorded on its first broadcast in 1967. By sheer chance, all but one of the scenes from the programme were included on a ropy compilation tape retrieved from a Swedish TV company, enabling the restoration team to overlay the soundtrack on the original images.

After a feverish trawl through foreign archives, the final missing sketch from the episode was miraculously discovered on a trailer broadcast more than 30 years ago in Australia. As a result, it was eventually possible to reconstruct the entire programme.

The episode will now be shown on BBC4 over the Christmas period, following a documentary about the ongoing worldwide hunt for missing archive comedy shows. In an interview in the film, Missing: Believed Wiped, Cleese condemns the "stupid" actions of broadcasters who were happy to wipe unique comedies and dramas while keeping copies of game shows and current affairs series.

"I've always found it astonishing that people could have wiped these shows," he says. "When I heard that the 1948 Show had been wiped, I kind of gave up. I mean you've got a show with Marty Feldman, Graham Chapman, me and Tim Brooke-Taylor and the answer is that it took up too much space. Can you imagine? What a pathetic argument."

To Brooke-Taylor, the 1948 Show bears as much of a relationship to his later comedy hit, The Goodies, currently undergoing a critical reappraisal after years of being derided as a poor man's Python, as it does to that series.

"Sketches had been tried before on The Frost Report, but the 1948 Show experimented with how to end them in an interesting way," he said. "In Monty Python, they just had a character coming in and saying, 'this is boring, let's do something else'. In The Goodies we got over this problem by just turning whole episodes into stories."

Among the other recently rediscovered comedy gems to be shown alongside At Last the 1948 Show, on 28 December, will be the first ever episode of Till Death Us Do Part. A one-off Spike Milligan experiment called A Series of Unrelated Incidents, and the only surviving episode of Morecambe and Wise's first series for the BBC will also be screened.