Len2307

Hello everyone out there - I hope I have put this question in the right place - I have never used a forum before!! Whilst sorting out my Dads possessions following his death, I came across a Concertina, that I remember seeing when I was a boy in the 60's and I recall he told me he was given this by a Polish man in the 1940's as a thank you for doing errands for him. It has a Lachenal & Co label with a serial number 152698 and has 13 buttons on one side and 13 plus 1 on the other. Its in a dark wood Hexagonal velvet lined Wooden box. Any information on what it is and the history of this would be fantastic. Thank you in anticipation of any comments or information