The Likely Lads creators on the unearthed episodes and what's next: "I'd like Olivia Colman to play Terry's mum in a remake"

It also made household names of the show's writers, Dick Clement and Ian La Frenais, who went on to even greater success with the Ronnie Barker prison comedy Porridge, the Brits-working-abroad comedy drama Auf Wiedersehen Pet, the screenplay for the film comedy The Commitments and countless other projects. Born in Essex and Tyneside respectively, they've lived in Los Angeles for 40 years.

Like so many programmes of the 1960s, The Likely Lads was the victim of the BBC's videotape wiping policy. Happily, two telerecordings – where a 16mm film camera was pointed at the TV screen – recently resurfaced in a private collection. Those episodes, from 1965, are A Star Is Born, in which Bob and Terry compete in a pub talent contest, and Far Away Places, where the lads plan a foreign holiday. Frustratingly, 11 of the original 21 episodes are still missing.

The memories came flooding back for Dick Clement, 81, who tells RadioTimes.com, "I directed those shows and it was a shock to realise how much about them I’d forgotten. Then in Far Away Places I started to remember the location filming that took place in Mill Hill in north London."

His friend and co-writer for 55 years, Ian La Frenais, 83, adds, "It was like looking through an old photograph album and being reminded of when we were very young and still learning how to work together. We were also beginning to wonder if there was anything we could write beyond The Likely Lads…"

So do they think the series would get to the screen now? If it did, what would be the key themes, and who would make a good Bob and Terry?

"I don’t see why it couldn’t work," says Clement. "Although so much has changed socially, the problems faced by young people are the same. But perhaps the lads wouldn’t be allowed to be so unabashedly 'on the pull'."

La Frenais adds, "Essentially it’s about class, friendship and being young. I think it’s timeless – although today the boys would have inside lavatories. It would be unfair to suggest casting as we’re not in the UK enough to know all the young actors available – though I’d like Olivia Colman to play Terry’s mum."

The episodes have been paired on both a DVD and Blu-ray release with the 1976 film, so what are the writers' memories of transferring the boys to the big screen? "We were keen to make it work as a movie and not just as an extended TV episode," says Clement.

Unlike the series, the film was shot in the North East, La Frenais points out, adding, "It was great to see so much of it on the screen, especially as it’s such a cinematic region."

But what has given them the most satisfaction? "It’s dangerous to make choices – like having a favourite child," says Clement. "What gives me most satisfaction is that we’re still actively pursuing our chosen career, most recently in the theatre [with the acclaimed West End play Chasing Bono]. Hearing a live audience respond is very gratifying."

For La Frenais, it's the range of their work as well as their longevity: "We fought being pigeon-holed at an early age and we’ve surprised people ever since. We have a similar way of looking at the world, so it’s mutual interest coupled with mutual respect and affection — and we’ve not done anything else since our mid-20s!"

Current TV favourites include Last Week Tonight with John Oliver and Real Time with Bill Maher(Clement), The Graham Norton Show and whatever the latest Scandinavian thriller series is (La Frenais). But do they ever watch TV together? "Mostly football when we take a break from writing at lunchtime," says Clement.

"We also watch shows that are pertinent to what we’re working on," says his colleague, "although a lot of that is on YouTube."

As for the secret of their chemistry, Clement responds, "When something works, it’s dangerous to overanalyse it. Writing on your own is hard and I know that some days I won’t come up with anything – then Ian arrives and it’s rare that we don’t achieve something by the end of the day."

The duo famously have a huge number of projects on the go – even in their 80s. Clement explains, "So many projects never happen that it makes enormous professional sense to have several on the go. At the moment they include three TV series: one concerns espionage, one football and the third is about the Kinks. We also hope to be adapting two novels, one English, one American."

La Frenais adds, "We have a screenplay written about motorcycle legend Barry Sheene and another about women’s curling – the sport, not the hairdressing. Stage musicals include one about Queen Victoria and another about Alice Cooper. You can place bets on which one of these will first see the light of day!"

The Likely Lads film, including the two restored episodes, is out on DVD and Blu-ray. To order the DVD for £10.99 incl p&p (RRP £12.99), call 0844 848 7300 (call charges apply) or visit radiotimes.com/likelylads, quoting ref RT1713