Hello, I have a Lachenal concertina. 25 Button inc, airvalve. Mahogany fretted ends. Five folds in the bellows. Lachenal and co label. Steel reeds stamped on the handle beneath the RHS strap. Number 182979. Passed along from Andy Grant of Warwick Queensland. Plays well I'm interested to find out when it was made. If anybody can help I would be very greteful. Cheers Seamus Duffy. ps I used Geoff Woofs mathematical system to get the date of 1893... Thanks Geoff.