The veteran cinematographer Bryan Langley (who shot several of Hitchcock's British films) tells the story of Gunn's lost thumb as if it is a cautionary tale to warn youngsters of the perils of working in the big, bad film business. Not long after Gunn's mishap, when Langley got a job at Gainsborough shooting The Stronger Sex (1931), he used to go and stare at the stub. "The lift shaft was still there, with trellis gates on it," he remembers. "Right at the top was a little white thing which we were told was George's thumb. We didn't know whether it was or not." When they weren't gawping at Gunn's thumb, Langley and his friends often wandered down to the nearby canal to see the debris blown there in the aftermath of the fire and to stare at the drowned cats floating in the water.
The picture he paints of the studio - dead animals, severed fingers, the whiff of arson - is not one likely to appeal to safety inspectors, but - as Langley recalls - film-making at Gainsborough was always as dangerous as it was glamorous. During the early talkie era, film-makers used unwieldy, highly dangerous carbon arc lights, "which always had red- hot ends coming off", says Langley. The celluloid itself was highly inflammable. To sound-proof the Islington studio, the technicians shrouded the entire building in thick blankets. "And these things caught fire." (The sound proofing wasn't 100 per cent fool-proof either. The film historians Ray Seaton and Roy Martin report that "at one time an Italian stone mason working hard next door had to be asked to switch off his drill while scenes were being shot".)
Fire, Langley adds (as if to emphasise that Gainsborough wasn't the only film studio run along death-trap principles), was an occupational hazard wherever you worked in the industry. "There were always fires going off - in film vaults and in studios. It was quite a common thing back then. Twickenham burned down. Elstree burned down too." Most studios had their own in-house fire brigades, but that wasn't something that the Gainsborough bosses were going to waste money on.
During the Second World War, production had to be abandoned at Islington because - as one of Gainsborough's biggest (if most reluctant) stars, James Mason, later noted in an acidulous article decrying "the drooling nostalgia" about the studio - "in the event of an air-raid, the huge power chimney was likely to collapse and crush everybody."
The film-making facilities at Gainsborough weren't impressive. There were only two sound stages, both little bigger than the average village hall. In the summer, it was often unbearably hot and in the winter, it was freezing.
"Compared to Pinewood or Denham, it was like chalk to cheese," says Langley. Hugh Stewart, who edited Hitchcock's The Man Who Knew Too Much at Gainsborough's Shepherd's Bush studio, concurs: "I was in the cutting room. It had no air so I smelt," he says of his first stint in Poole Street."
The more you discover about the physical circumstances under which films were made at Gainsborough, the more the studio sounds like an old-fashioned sweat shop. Movies were shot at breakneck pace. "Eighteen days, that sort of thing - it was very hard work," remembers Langley, who used to work on at least 10 films a year. He paints an almost surreal picture of how The Stronger Sex, an early talkie, was shot. "We worked in a booth, like a tardis. We were stuck inside that booth... when sound began, everything was rigid and locked in."
Last week, when the British Film Institute launched its celebrations of the centenary of Hitchcock's birth with a reception at Gainsborough, dead cats and missing fingers weren't on the agenda. The BFI's chairman, Alan Parker, a self-proclaimed "hooligan from Islington", opened the event by cutting a piece of film with a large pair of scissors. Afterwards, the various elderly actors and directors (Langley and Stewart among them) bussed in for the event fraternised with journalists, industry executives and BFI bigwigs. There was talk that movie-making might soon return to this neglected little corner of nether Islington ("a frontier post in the slums" as it was once described). Developers are giving Gainsborough a make-over, planning a new restaurant, new flats, new work units and - most importantly - new film-making facilities.
Nostalgia hung heavy in the air as the old-timers reminisced over the tea and buck's fizz. It was here that Hitchcock shot The Lodger and The Lady Vanishes; here that Ivor Novello (Britain's very own answer to Valentino) danced that ferocious tango in The Rat; here that the Crazy Gang headed to the Klondike 100 years late in the lunatic gold rush comedy Gasbags; here that Phyllis Calvert and Patricia Roc (whose colourful love-life earned her the affectionate nickname "Bed Roc") experienced life in a concentration camp in 2,000 Women. Gainsborough movies rarely pleased the critics, but, whether they were the Thirties comedies or the baroque Forties melodramas, they invariably did well at the box office. The studio's trademark motif - the oval portrait of the busty "Gainsborough Girl" looking like Nell Gwyn - was, in its day, as famous as Rank's muscleman walloping the gong.
It remains to be seen what sort of films, if any, will be shot at Gainsborough in the future. "You couldn't really make a Bond film here," Langley remarks dryly. The studio (which is already hosting a Hitchcock exhibition) is sure to take its place on the heritage trail. Since Rank sold it in 1949, it has done service as a carpet warehouse and as a whisky depot. At least now it has achieved a little belated dignity. And what's more, Gunn's thumb is nowhere to be seen
`The Ultimate Hitchcock Exhibition', Gainsborough Studios, Poole Street, N1 1pm-5pm until December. Free