Esquire from Fr "
escuier" = shield bearer. And a very important mechanic to have with you a millennium ago when a few thousand knights had to
terrorise subjugate a population of a couple of million. I find the
entry in Wiki one of its better ones - tracing the evolution of the word from essentially a trainee knight to something the London cabbie now drawls over his shoulder "whœre to, squære". A legal use is there too - squire remains an official term in Scotland!
Back to topic - this suggests our melodeon repair man should be an "
accordéonier" - which a few hundred years more social history will doubtless abbreviate to a cryptic "cordie". Gosh - I've made up a word
You are. It's akin to referring to yourself as "Mr.", which my Daddy warned me was a sign of ignorance and pomposity.
[edit] Oh Steve, you've missed out several layers of the old English class system (as elaborated above by Ukebert). Throughout the '45 war Hitler was repeatedly referred to as "Mr" - not only by Churchill - to indicate his that his pedigree came from the lower strata of society.