Since I haven't had the chance to read 'the carpet fitter short story', it's difficult to be certain. However, the carpet fitter is most likely a main character. There could also be other characters like the store owner from whom he gets the carpets, or perhaps a coworker who helps him with the bigger jobs. There may even be a character who is a difficult client and causes some sort of conflict in the story.
Not having read the story, it's just speculation. The carpet fitter is surely a main character. Maybe there's an apprentice who is learning from the carpet fitter. And there could be a regular customer who has specific requirements and whose story is intertwined with the carpet fitter's work, adding depth to the narrative of the short story.