Simon Day’s fans are so dedicated they’ve copied his look, with plenty of bald middle-aged white men in the audience of Southampton’s Stage Door venue.

And he very much plays to his demographic, evoking a nostalgia going further back than his 1990s stint on the Fast Show, with gags referencing the likes of Tony Blackburn, Emmerson, Lake and Palmer, The One Show forerunner Nationwide.

It evokes the era of his alter ego Brian Pern, the 1970s prog rocker still very serious about his music. Although one of his most successful creations, Pern is not one of the five he presents on this tour, four live and one on video.

The comic takes to the stage in character with no fanfare, which sets the tone for a show that has little verve, and often seems under-written and under-rehearsed. He flunks several lines, while some routines fade into thoughts without punchlines – even though the execution of his characters is always strong.

First is his most enduring creation, the pub know-it-all, Billy Bleach. It’s in fitting with the character but the ‘you can’t say anything any more’ shtick feels tired.

He’s no bigot – the Proud Boys-style polo shirt notwithstanding – but a bore, and his long-windedness doesn’t inject the room with much energy, even if it does carry some enjoyable phrase-making. He’s at his best when giving a glimpse into his home life, and there’s an especially nice segment about shouting unintelligible comments at his son’s football game, a perfect recognisable parody.

But it’s an inconsistent script and leans heavily on a bar-room gag involving a talking rabbit. Bleach is just the sort of person to trot out such second-hand jokes, of course, so it can probably be excused as a Barry Cryer-style celebration of the form.

Costume changes are covered by videos of Day as a builder, admirably accurate in portraying the friendly dodginess that will be familiar to anyone who’s had work done on their home. But it’s slow-moving and repetitive once the persona’s established, especially for anyone used to the taut discipline of online comedy sketches. It would be twice as good if it were half as long – even before the geezer reappears in part two to cover a second scene change.

Day next presents another old favourite, Tommy Cockles, with reminiscences of his days in the music halls and wartime concert parties – ‘they really were marvellous times’, he repeatedly insists, despite evidence to the contrary.

This is his most playful character, embracing the delightful anecdotes and obscure name-dropping of old-school entertainers, rich in details such as the titles of fictional Arthur Askey films. As with Bleach, the stories may not really go anywhere, but the cheery, thespian delight he takes in telling them is infectious.

After the interval, we meet Tony Beckton, the violent ex-con, clearly in the mould – and moustache – of real-life hard-nut jailbird Charles Bronson. He might not seem to have much in common with Cockles, but at their core both take real-life incidents – the 1990 Strangeways riots in Beckton’s case – as the starting point of elaborate alternative versions.

The faux reality of Beckton is quite grim, from being verbally abusive to his wife to striking up a relationship with a woman who seeks partners behind bars. Again it seems credible, even given the fantasy exaggerations.

After the return of the builder, we end not on a high but with Geoffrey Allerton, an Alan Bennett-type poet from Harrogate, whose parodies don’t have the wit or eye for detail of the original – nor anything that makes them a parody, really, just pale imitations of the original.

Sadly, it ends up being a sluggish, tired night - several times Day has to explicitly ask for a round of applause only to receive the limpest of ovations – which comes as a disappointment as the characters are so convincing.

His stock-in-trade is long, surreal anecdotes that offer an insight into the credibly eccentric world of his creations, but even within those parameters, the scripts here need tightening. Even more crucially the evening needs a sense of occasion, for at the moment it feels more like a work in progress than a finished product, despite the occasional brilliant flashes.

• Simon Day And Friends is on tour until November 26. Simon ​Day tour dates