Very interesting, and well done, with a lot of patience. At every stage you must not forget to keep the camera rolling, and afterwards a lot of cutting and pasting. Amazing! Thanks for posting. The builder has on his Youtube account also an interesting demonstration of tuning the tempered third.
Thanks for posting! I will send it on to the Dutch builder Karel van der Leeuw.
Actually i believe it is that fast a process. I once heard that accordion builders take an oath to never deliver a finished accordion before 12 to 18 months to give the appearance of a very intense and complicated process.That way they can keep prices inflated and interest at a maximum.. Just sayin'...