You are correct Headingwest. On my first flight from London to Cyprus in 1958 ( on a Vickers Viscount), I recollect clearly the title Master on my ticket.

On most tickets, the abbreviation Mstr will have been used instead of Master since. according to etiquette, this is the correct way to refer to a male child. I have seen reports of Qatar using Mstr on tickets as little as three years ago.