Mais mon RP, you bring me back to my early years with that question about the tight bellows. I think that because it is a Hohner Ariette, the bellows are tight. Those Ariettes are a curse on the unsuspecting and inexperienced would be Cajun accordion player. The fire may be the best place for it. I've owned 5 accordions in my life and I never had a problem with bellows being too tight on them. 3 were Cajun made and 2 were Italian made(gabbi's) I'm wondering if the two holes that let the air flow from the bellows compartment to the reed compartments are too small on an Ariette?? When you play any accordion, you have to use that air regulator button on the back of the bass block. It is an absolute must. Try working on that before you start pulling the living hell out of them bellows trying to make them loose. You don't want to weaken the cardboard corners or they will start to leak way before there time. Try to appreciate the tightness. I have played on a few accordions that the bellows were way too loose. Like $20 w.h.o.r.e.s they were.
And then there's that other thing....the bellows are the short bellows type, then the solution is to get new bellows. Short bellows tend to be a lot tighter for the player. Got dam things don't have no extension give! I don't even know why they would make short bellows. If you don't understand...go buy one of them gas station toy accordions for $20 and play on it. You'll see what I mean by bellows being way too short and hard on the accordion player.