This is largely speculation, but I would have thought it depends on how popular 'widget plumbing' (the suggested term) is.
If you establish his brand name firmly on the web, Google will have signals that what they currently view as a mis-spelling of a search term is actually a term in its own right. They might stop rewriting that result.
Another factor that could help is if significant amounts of customers keep correcting them. Google can learn, and a recent thread here reported that suggestions can vary by zip code.
But I would have thought the key factor is the occurrence and demand of the suggested term. The greater the demand for that, the less likely I would have thought that you can do anything about this.