According to Bill Bailey, you can make any piece of music into Cockney by adding these words at the end of a verse:

"Oi!!" and "'Ave a banana!"

As in :
"...... Go-od save the Que-eee-en...
Oi!"
And:
".... we'll tak' a cup o kindness yet, for auld
lang syne.. 'Ave a banana!"

Works for me...

Cheers

Steven