I don't know if it's of any use to you - it's not really the right period - but the young Huddie Ledbetter (Lead Belly) was playing a windjammer accordion at the end of the nineteenth century. Also, you might like to take a look at E. Annie Proulx's recent novel 'Accordion Crimes', which, as well as being an entertaining read, also features a limited bibliography of sources used to write the book, some of which might of use to you.

Best of Luck Brian