DavetG and Banjoman, even anyone with only their dayskipper ticket knows that safety regulations include taking aboard an accordion and a banjo, the accordion as you say for pumping out, but the banjo for paddling if the accordion fails.

Lachenals certainly mass-produced their 2-rows for the bottom end of the market and then towards the end of the 19th century came those mass produced German imitations with banked reeds which were much cheaper. With their paper bellows they wouldn't have lasted long at sea but the Lachenals were robust enough.