Following on from the Aeola 64 key baritone-treble concertina, serial number 28617, that was recently sold on Ebay, I came across a link to a Canadian website with an article about concertinas. By coincindence, it happens to feature the next concertina down in the ledgers from 28617, 28618, also a 64 key baritone-treble, which has survived and is owned by someone in Canada. Both are wrongly marked in the ledgers as a model 20, which is a baritone only. It should be a model 16. There is also quite a bit on the history of concertinas, albeit with the odd mistake here and there. Quite possibly, these big Aeolas were made specially as band instruments, either for playing in concertina bands or for the Salvation Army. Here is the website address.
http://www.thecanadasite.com/antiques/concertina.html
Chris