"Barney's Epic Homer" is sung by Chris Foster on "Traces" (Green Man, 1999). A review contains the following quote:

"Barney's Epic Homer" is by Leon Rosselson and concerns Barney, a young man who marches to his own drummer and who seems doomed to a job on an assembly line "Turning little piggies into / Plastic packaged sausages / To sell in the heliport canteen." One day, he finds a means of expression, which, sadly, is deemed unacceptable. Still, you cheer for Barney and perhaps resolve to try to see the world a little more through his eyes.

...and another review of the same album says

Of the two Leon Rosselson songs, my favourite is "Barney's Epic Homer" - a daft, but underlyingly sad and haunting tale of a disaffected schoolboy doomed to a production-line job, "turning little piggies into plastic-packaged sausages". Barney rebels by building a giant, scrap-metal sculpture in his parents' garden. When this is demolished, he sinks back into despair and anonymity. Chris Foster gets the perfect balance of jaunty silliness in the story and pathos as it reaches its sad end.

It's also on Leon Rosselson's album "Guess What They're Selling at the Happiness Counter."