Translating Cockney

The following passage is lifted from the book Shadows of the Workhouse by Jennifer Worth and is taken from "Part II: The Trial of Sister Monica Joan". To give background, in the 1950s the 90-year-old Sister Monica Joan had been accused of petty thievery in the market and then grand theft when a pile of jewels were found unaccountably in her possession. Sister Monica Joan was taken to trial and several costers (hawkers of fruit, vegies, fish, knick knacks, etc) were there to give their testimony to the light-fingeredness of the Sister. In giving testimony however in their cockney, an assistant to the court gives a very clear-cut translation and explanation on how cockney is used:

The costers were called to give evidence. They were a colourful group of seven men and one woman. The first stepped confidently into the witness box to be sworn in, giving his name as Cakey Crumb.
"Could you give your first name please?"
"Well, I've allus bin known as Cakey. Wiva name like Crumb, wha' would you expec'?"
"With what name were you christened?"
"Cuthbert."
Shrieks of laughter from the costers, which were silenced by the judge.
Counsel for the Prosecution continued: "Could you please describe your occupation?"
"... Costermonger. I 'as me own cock sparrer, an' sells in ve park its."
The judge interrupted. "Did you say you sell cock sparrows in the park its?"
"No, no m'lud. Cock sparrer is wha' we calls ve barrer an' park it is ve market."
"I see." The judge made a note. "Please go on."
"I sells ladies fings, and vis nun, she comes up to me stall an' afore you can blink an eye, she picks up a couple of bread an' cheeses, tucks 'em in her petticoats, an' is off round the Jack Horner, dahn ve frog an' toad, quick as shit off a stick. I couldn't Adam and Eve it, bu' vats wot she done. When I tells me carvin' knife wot I seen, she calls me an 'oly friar, an' says she'll land me one on m' north ad south if I calls Sister Monica Joan a tea-leaf. Very fond of Sister, she is. So I never says nuffink to no one, like."
The judge had laid down his pen long before Cakey had finished giving his evidence. "I think I am going to need an interpreter," he said.
The usher spoke, "I think I can help you, My Lord. My mother was a cockney and I was brought up with the rhyming slang. Mr Crumb has testified that he saw Sister Monica Joan take a couple of handkerchiefs - bread and cheese is the usual expression for handkerchiefs - off his sparrow, or barrow, and set off round the Jack Horner - corner, My Lord - down the frog and toad - meaning road - as quick as - I need not go on, my Lord, a harmless vulgarity implying no disrespect to Your Lordship - quick, stick - the rhyming is obvious my Lord."
"I am beginning to understand. Ingenious, very. But what was all that about Adam and Eve? We are not talking about the Garden of Eden, you know."
"'To Adam and Eve it' is a very common expression my Lord. It means 'to believe it', or the negative. Mr Crumb could not Adam and Eve the evidence of his own eyes."
"You are very knowledgeable, usher, and I am indebted to you. But that was not all the evidence Mr Crumb gave the court, and it has to be written down for the record."
The usher was standing up stiff and straight and feeling very important. All eyes were upon him. "Mr Crumb said that he told his wife what had happened. There are several expressions for wife - carving knife, trouble and strife, Duchess of Fife spring readily to mind - and she called him a liar - holy friar, My Lord, and said she would hit him in the north and south - mouth - if he called Sister Monica Joan a thief - tea-leaf was the rhyming slang used by Mr Crumb."
"I understand now. Thank you, usher." The judge turned towards Cakey. "Would you say that that interpretation is substantially correct, Mr Crumb?"
"Oh yerst, yers. That's Isle of White."
"I suppose I am correct in understand that it is ... right?" The judge looked pleased with himself and smiled at Cakey. He motioned for the Counsel for the Prosecution to continue.
"When did all this occur?"
"Abaht a year ago, I reckons."
"And you never told no one - ahem, I mean, anyone?"
"Nah, nah. I'm no' daft. There'd 'ave bin a righ' 'ole bull and cow if I 'ad. I don't want me jackdaw broke, do I?"
The judge sighed and looked towards the usher.
"Mr Crumb did not tell anyone, My Lord, because he was anxious to avert a row with his wife, whom he felt was capable of breaking his jaw."
"Is that correct, Mr Crumb?"
"Gor, not 'alf, an' all. Got an Oliver Twist like a piston, she 'as. Knock yer 'ampstead 'eafs out soon as look at yer, she would."
"Thank you, Mr Crumb, I was referring to the accuracy of the usher's translation, not to your wife's skill as a pugilist."
"Oh, I see. Well yers, 'e's got ve lingo taped an' all."
"Thank you, Mr Crumb. Usher, I should be grateful if you would attend closely to what the witness says and interpret for me, should it be necessary."
"Certainly, My Lord."
Counsel for the Prosecution continued, "Having said nothing for a year, why have you come forward now?"
"Because I earwigged some of me mates 'ad seen ve same sort of fing; vis old blackbird goin' round ve markets, lookin' all 'oly like, bu' pinchin' fings off stalls and then scarperin'. So we goes to ve grasshoppers, an vey took it to ve garden gate."
"I understand your evidence as far as the grasshoppers, Mr Crumb," the judge interrupted. "Usher, perhaps you could enlighten me as to the meaning of the last sentence?"
"Grasshopper, My Lord, is rhyming slang for copper, which Your Lordship may know is a colloquialism for the police. And the police referred the case to the magistrate - the garden gate."
"I understand." The Judge turned to Mr Crumb. "If the police are grasshoppers and magistrates are garden gates, what, may I enquire, is a judge?" he asked politely.
"Barnaby Rudge, m'lud."
"Hmmm. Not too bad. Could have been worse, I suppose. We might have gone down in local terminology as a pile of sludge, or something equally unsavoury. All things considered, I think we have been let off quite lightly. Counsel, do you have any further questions?"
"No, My Lord."
Cakey Crumb stepped down from the witness box, and a costerwoman took his place ..."

by Jennifer Worth in Shadows of the Workhouse, (2005) p 186-8.