Here is the schoolboy as wily innocent, the termagant wife in her turbaned headscarf, the husband cowed into immobility, and, in the eponymous grandad, the rascally, anarchic scourge of all lace-curtain propriety. This old man is, he swiftly informs his grandson Gil, 'daft enough to know I'm daft'.
His is a daftness to delight an eight-year-old. He has an enviable repertoire of belches and farts and his phlegm whistles unerringly where he listeth. Grandad is also a con man who can sell a Conservative councillor a cock's egg. But even Gil turns queasy at his tales from the trenches of loose heads, eyes, and a bag of ears mistaken for liquorice allsorts.
As played by Gordon Wharmby, Stott is never really genial but protects a side, perhaps even a core, that is enigmatic and sinister. This dark side got him through the war, which he survived at the expense of officer-toffs who had to be 'shot for being a pillock', and it got him to the war in the first place, escaping as he did from a pregnant girlfriend.
All this is meant to complicate our response to the old devil, but Gil (Graham Gill) is also our narrator, and his identification is so complete we are encouraged back towards hero-worship, especially as the play's concluding 10 minutes explain and justify Grandad's incorrigible fecklessness.
Up till this point, the play has been a string of episodes and anecdotes with the only plot movement being the gas explosion that obliges Grandad, unscathed of course, to exchange his own smouldering armchair for that of his desperate daughter (Sherry Ormerod). Though sporadically funny, the play misses the tribulations of comic narrative that were so effective in Stott's hit Funny Peculiar, and draws out the single joke of the scurrilous OAP to breaking point, just as the cameo of the ineffably hesitant doctor is so plastered over that even the skilful work of David Ericsson eventually disappears beneath it.
The ending is programmatic, though with a neat denouement nicely realised by the blank doors that open and close in Gil's revelatory dream (set Keith Orton). Its message installs Grandad as the heroic refusenik who wins against the massed forces of domesticity, respectability, education, jobs and mortgages by simply opting out. Rather less comfortably, he's also virility escaping the strident femininity that has emasculated Gil's docile Dad.
This conclusion is rushed, and the comedy would not have been diminished had the essential conflict between Grandad and daughter been more even and less heavily caricatured. It is she who repeats Al Read's catchphrase, the dire threat 'Right monkey', but it's Grandad who has the first and last laugh.
To 12 Feb (Booking: 061- 624 2829)