That's not Cockney. That looks like someone writing very broad Yorkshire dialect as it is spoken. I think 'Ahthowt' means 'I'll tell thee for nowt.' 'Thee' is an antiquated word for 'you' and 'nowt' is a word used in northern England to mean 'nothing.' I have family from Yorkshire, I recognise the manner of speaking. But other opinions are welcome. So putting that into standard English, this is a rough approximation of what I think is being said. And I'll tell you this for free, United would have run rings around them. Well, they ought to have done. And they would have done if they'd only tried a bit.

That's Yorkshire or Midlands... t'United = the United (Manchester United) rahnd = 'round = around owt = ought 'a' = have (notice the two apostrophes!) they' = they'd've = they would have nobbut = naught but = only To "run rings around" someone means to be so superior that you could run faster than something even if you kept running around and around them while they were running! Hence, Su.Ki.'s translation.

This isn't definitely isn't Cockney. It's more like the stereotypical speech of someone from a county such as Yorkshire, in the north of England. My guess at a 'translation' into standard English would be 'I thought United would have run rings round them. That's what they ought to have done. And that's what they would have done if only they had tried a bit'. It's a comment about the result of a football match. The speaker thinks that United could have easily beaten the other team, but they didn't beat them because they didn't make any effort.

@Paul ought and nought rhyme with caught here, but not usually with short. (and "nought" is sometimes pronounced the same as "not") Sorry, I see what you mean; when you said "tell thee for nowt" and you translated "owt" as "ought" I thought nowt was another way of saying "nought" or "naught" ;I maybe they had a similar origin. "ought" means "should " in the US and as far as I know we dont have any meaning that means "anything". I love regional English variations, like in the show "The Last Tango in Halifax", where the actors try to lay on a thick northern accent.

Ah JB Priestley! Given that context it is likely that 'United' refers to the fictional 'Bruddersford United' in that case.