I'm in Lincoln! Plus, I've done a bit of fettling. I'm by no means an expert but I know quite a bit about these instruments, and how to tinker with them. I'm away at the moment, but when I get back in a couple of days I'd absolutely be up for giving you a hand. I'm also only a teenager - 19, to be exact - and I know that accordion fettling isn't exactly bank-account friendly if you're young! Also I believe your buttons are probably casein, which was used extensively on old boxes. I'm not quite sure how to clean casein, but be careful either way.