The story of my wife's paternal grandparents first meeting about 1900 is that she had gone somewhere on Tyneside to take message to one of the men in the family. May have been at Seamen's Mission. There she saw a Norwegian sailor, in his sea-boots, smiling as he played the concertina.

Use of the concertina by seafarers has to be relatively recent. Was it a decade or so after Waterloo that they were developed?