I am selling both of my English system concertinas in order to help fund my business startup. They are both listed on eBay:
Lachenal - http://www.ebay.com/itm/Lachenal-New-Model-56-key-Extended-Treble-Concertina-w-Case-circa-1892-VGC-/141665565548?ssPageName=STRK:MESE:IT
Wheatstone - http://www.ebay.com/itm/C-Wheatstone-Co-Model-1E-48-Key-Treble-English-Concertina-w-Case-1959-VGC-/141665565551?ssPageName=STRK:MESE:IT
I would prefer to sell them here, I will make a site donation as is customary should they do so. Please ask any questions you may have about the instruments.