treewind:"Wheatstone and Lachenal Dates of Manufacture"
concertina.info/tina.faq/conc-ap1.htm

RE:If you check the origin of that article you will find that the true serial numbers do not start with "number 1" at all. As a matter of fact the first hundred or so products are quite a bit obscure but some precise information is available too.
You find copies of the original Wheatstone books here:
http://www.horniman.info/WNCMARC/C104A/INDEX.HTM

and you will find that the first (interpreted) entry is 03 May 1834.
Further research can date the earliest "known" instrument (not named a "Concertina" but a "Symphonium with bellows) a couple of years back, but not to 1830 ( from my memory,I can check better later)