I'd played the first bit, no problem. And I got to the one note that's on the other row, and no sound came out. Hrmmm...
A few screwdrivers later, I had one side open and was peering inside her bowels. I immediately learned several things about my concertina:
1. The bellows are mostly thick paper, with just the corners being made of leather. No surprise there, as she cost something like 130 bucks.
2. The reeds are actually accordion reeds, not concertina reeds. No surprise there, either, as most sub $1000 concertinas have accordion reeds (bigger supply, easier to get ahold of).
3. Her name is Ira. It's scrawled on the inside. Okay, so that's probably the name of the assembler, but I prefer to think they name all their instruments.
4. The reeds are held in place by wax, which is not very good if you leave your concertina in the heat. Hence...
5. Three of Ira's reeds had come undone and were just hanging out wherever.
So now comes the puzzle. Each reed is double-sided (one note per side), and it's not immediately clear what vertical alignment to choose, either. Also, there's no way of knowing which one is which.
Several permutations (and screwing and unscrewing later), I find my fingers covered in gooey wax, and the concertina back in perfect condition. Ermmm... except for the fact that one of the reeds will not play the D it's supposed to, maybe because it's covered in too much wax. But meh. I've got the same note on another button. See, they built in redundancy. I admire that.