WHEN the playwright William Goldman bought a ticket to see Staircase on Broadway in 1968, he was shocked to read the programme.
It seemed to him that, in their biographies, the creative team had gone out of their way to stress how straight they were.
Charles Dyer's play had been written as a respectful examination of gay life, but what was on stage in New York, reckoned Goldman, was "a charade".
A similar fate befell the film version. Someone had the bright idea that this story of two ageing homosexuals running a Brixton barber's shop would be a perfect vehicle for Rex Harrison and Richard Burton.
But the only thing that made sense for such heterosexual icons - and their marketing department - was to treat it as a camp joke. Released in 1969, the film flopped, appealing neither to the mass market nor to a gay audience.
"I saw a clip of it and it looked appalling," says Andy Arnold, who is directing and starring in the Scottish premiere at Glasgow's Tron.
"The film got slated and quite rightly so, because they sent the whole thing up and did it as two camp comedy characters. It is very funny, there are very witty lines, but actually it's a very dark, sad piece of theatre and the two characters are very serious."
It was a different story on Staircase's debut with the Royal Shakespeare Company at London's Aldwych in 1966. Paul Scofield and Patrick Magee played the aging barbers, one masochistic, the other sadistic.
Of Peter Hall's production, The Times said: "Mr Scofield, blanched and desperate, runs through the whole repertoire of male effeminacy without once approaching theatrical clich."
Admittedly, that was only after the Lord Chamberlain had excised many contentious exchanges, but in those days, when the British stage was censored and homosexuality was illegal, Staircase was seen as a milestone.
It is a portrayal of two men - one with the tell-tale name of Charlie Dyer - whose witty banter turns ever darker as details emerge of the impending arrival of a daughter from a previous, even more closeted life and a court case for propositioning a police officer.
"It's fascinating historically," says Arnold, "which is why it has to be set at the time - you wouldn't update it - because it's not that long ago and yet the landscape has changed so dramatically.
"These two people are living in the denial of their sexuality, the shame of it and the fear of legal repercussions. It was also a time when there was this incredibly rich vein of theatre writing."
So why has it taken nearly 50 years to reach Scotland? "Good plays do get forgotten about," he says, recalling the stagings of lesser-known plays he has done by famous writers, such as Eugene O'Neill and Arthur Miller. Admittedly, as tastes change, some might find Staircase, in its original form, to be too drawn out. "We're doing a trimmed-down version, it's tighter and more dramatically powerful," he says.
"In the West End production it was a happy ending, but there's an author's note in the script which gives a more interesting alternative ending, so we've employed that. I think it's a brilliant play. The quality of writing is easily comparable to Harold Pinter."
Arnold insists the new staging of Staircase does not rely on any special topical resonance, such as the current debate about same-sex marriages and church weddings. "I don't think that's what people take from the play," says Arnold, who is acting opposite Benny Young.
"There's a fascinating historical insight into what was happening at that time, but the play itself is a piece of drama in its own right, which is not about any social politics or developments in terms of gay culture.
"It's much more a play about a power struggle between two people, as all good plays are. It's a story that keeps on unfolding and has a twist at the end, and that's what people take from it."
What they can also take from it is the chance to see Arnold on stage, a frequent sight in the early days of the Arches Theatre, but not since he took over at the Tron.
"I'm one of these old-fashioned directors who believes you get a greater insight into the stage craft of actors by doing it yourself occasionally," says the man whose last major role was in Pinter's Moonlight in 2005.
"I love acting, but it's been a bit of a luxury in recent years because there's too much else to do. It's reminded me what hard work it is - it's quite exhausting."
Staircase,Tron Theatre, Glasgow, Wednesday until 5 March. www.tron.co.uk
This article was first published in Scotland On Sunday, 20 February, 2011