Peter Sellers called it "a terrifyingly bad film" and his promised percentage of the takings was little more than £33. But Penny Points to Paradise is something of a missing link and has been hardly watched since its release in 1951.

Tomorrow , an audience at the British Film Institute will watch Sellers and his two co-stars, Harry Secombe, as a gormless pools winner, and Spike Milligan, as his best friend, clown around in an amiable seaside crime caper.

Shortly after, all three entertainers went on to transform British comedy with the Goon Show.

The BFI regards the restoration as a significant one, a "missing link in British comedy history". The institute's curator, Vic Pratt, said: "You are able to see them at the beginning of their careers. The film captures the moment as they are about to revolutionise comedy with the Goon Show and it's really important for that reason."

A DVD of the film will be released next month and while the movie is, as Pratt admits, "a bit rough around the edges", it is not as bad as Sellers remembered.

Sellers, in particular, shines in his two roles as an old major and a smooth talking salesman, Arnold P Fringe. "In Peter Sellers, you see a talent that was fully formed from the beginning and he clearly knows how to use the camera," said Pratt.

The restoration is about as close to the original as is possible. It came about after Kate Lees, granddaughter of Arthur Dent, who ran Adelphi Films, was sorting through material once stored in the company's production office. Gathering dust were two reels of rather battered 16mm film labelled Penny Points to Paradise.

The restoration has been funded by Laura Camuti, an American and a Sellers fan, who said she had grown up loving the Pink Panther movies. She said: "I became aware of how much of his career I didn't know about. I didn't know about the Goon Show, for example."

She too believes the film is much better than Sellers thought. "He was often terribly critical of his own work," she said. "I appreciate that it's nothing like the level of Dr Strangelove but I really enjoy his performances in this film."

Penny Points to Paradise, which is set in Brighton, also features very good performances from actors who would go on to make names for themselves – Alfred Marks, as the cigar chomping bad guy, and Bill Kerr, as his sidekick.

"It's fair to say that it's a bit rough around the edges," said Pratt. "It's a cheap and cheerful film that was filmed in just three weeks.

"But it is particularly interesting because you are seeing most of the Goons just before they made it big and you see them honing their craft. Spike Milligan isn't playing his normal role, he's almost the straight man, while Harry Secombe is the central figure."

Also on the DVD are two similarly obscure films getting an airing.

Let's Go Crazy, which was filmed to use up a week of studio time left over from Penny Points to Paradise, features Sellers in a series of restaurant comedy sketches playing characters with names such as Crystal Jollibottom and Izzy Gozunk.

Milligan is also included in the footage, playing an early version of his Eccles character from the Goons.