I'm sorry......my intention was not to ask such a complicated question.
Your definition would be correct IF used in the context as an ADJECTIVE, as in: "A carburetor is a "specialized" fuel control device."
In my quoted question, SPECIALIZED is used as the VERB in the PREDICATE of that sentence. It refers back to the NOUN "Ken" in the SUBJECT, as in: "Ken specialized in........" If you can remember back to that awful "diagramming of sentences" when we were in grade school, it still works to help make our language specific, yet simple.
So more-specifically, was Ken SPECIALIZED in selling carburetors, etc, or buying carbs, or talking about carbs, or beadblasting and spray-bombing carbs?