Vera where did you get your bellows for the button?

Thanks for this Vera. I have exactly this problem. I am not sure yet whether it is the bellows inside the button, or the "Concertiana" diaphragm as you have called it that is causing the problem. I would like to buy a new one of each. (They can't cost all that much ??) Have you got an online supplier for these that you could let me know?