Hello all. I just purchased a concertina with the label Rigoletto. It has 20 buttons and is missing the air button. I don't know much about this instrument except that I have always loved Irish tunes, loved the sound of the concertina and wanted to learn to play it. From what I can tell, the other buttons are in working condition and seem to be even with one another. (If you can understand what I mean.) I don't know much about what an out of tune concertina should sound like. The bellows seem to be in perfect condition. But, truly, I am a newbie (although I sing and have played the fiddle.) So my first question is, where can I find an air button for replacement? Is that something I can fix myself? I am not sure how old the instrument is. It is very sweet looking. Any help?