‘It’s funnier than we thought it was going to be.’ That seems to be the unanimous verdict of the celebrity Blackadder fans given a first look at the show’s pilot episode, which had been languishing in the vaults for 41 years.

Excitement at the discovery of a previously unaired episode of a classic comedy is tempered by a nagging feeling it might be awful. It was, after all, never intended to be seen and came before what is widely considered the least funny of all the Blackadder incarnations.

But – made public tonight as part of Gold’s 40th anniversary celebrations for the show – it’s pretty good. Flawed, certainly, but very watchable not just for its curiosity value – as well as being a fascinating insight into how a TV comedy show evolves, for all those interested in such nuts and bolts.

As several of the commentators in the preamble point out, the Edmund Blackadder of the pilot is closer to the more arrogant, scheming character of series two and beyond than the simpering Edmund of the first series. How odd, then, that writers Richard Curtis and Rowan Atkinson moved away from what would become the most successful elements – requiring Ben Elton’s input to rediscover the funnier dynamic.

Atkinson’s character in the pilot can be inconsistent, snivelling before his father, for instance, when for the rest of the show he’s a more alpha sort, plotting revenge on the treacherous Scot McAngus (Angus McNorton) who has cost him his inheritance. Meanwhile. Baldrick – played by Philip Fox in the pilot rather than Tony Robinson, who presents this programme – seems to be of surprisingly average intelligence.

As Curtis now acknowledges here are too many characters, and pacing can be sluggish – including a clunky play-within-a-play and long duel in which Blackadder proves himself a surprisingly able swordsman. And the character had not yet developed the extravagant  insults which came to define the show. Instead, there are more puns than you would expect.

Yet you can see so much that works, too – at least with the benefit of hindsight. (Talking of which, a scene in which Blackadder gets his head stick in a knight’s helmet foreshadows one of his most famous Mr Bean moments). The premise is strong – despite BBC executives reluctance to commission a historical comedy – as is the conniving plot, and, of course, Atkinson’s grandstanding performance.

Added to which there are plenty of interested tidbits in the introductory interviews – such as the fact that one of Blackadder’s hats cost more than Curtis was paid for his script.

Miss this and you’d be more stupid than Ronnie McStupid, who would have won last year’s world’s most stupid man contest, had he not been too stupid to catch the right train.

• Original Blackadder: The Lost Pilot air on Gold at 9pm tonight

»Read Tony ​Robinson talking about the pilot here.