I would be interested to see any reference to the use of concertinas in a CW setting. I have not yet found any. It is not that they did not exist but rather how popular they were in use. It is well documented that these melodians were in wide use at that time. They were designed for portabilty, for travel. Do not think that all a soldier did was march. Many spent extended periods in camps. Many entertainers and merchants followed these camps and there was also plenty of teamster hovering about. There is an awful lot of furnature in some of the photographs! I do have several photographs of soldiers posing with the period style accordians. These can also be seen as part of fiddle and banjo bands which was the big musical trend.