This character was indeed from Glasgow, and as far as I'm aware his "troublemaking" wasn't to do with "busking" in any musical sense, but with making it his business to publicize instances of inefficiency, nepotism, corruption generally among City Councillors and the like. Unless I'm confusing two things, either he, or an early form of "Samizdat" news-sheet he produced, was known as "The Clincher". Real "busking" anecdote follows.