The Complete English Poems question

We have a cassette tape of my great grandad singing songs and reciting poetry/monologues etc. There's a particular piece that I've looked for online, with no success. It's about a boy named Tim, Little Tim. From memory the tale revolves around Little Tim's late father's friend, who defends Tim in a pub/bar and strikes a blow to the person who attacks Tim. It's as if it's in a court and the man advises the court that he promised Little Tim's father he'd take care of Tim. It begins: 'Yes, it was me, the prisoner said. As he wiped his brow and bowed his head. Guilty of all the things you name, but this poor boy is not to blame.' etc... Does anyone have any information about this at all? It would be greatly appreciated. Thanks