Agreed Paul, the fretwork was the first thing that made me think George Case, and the papers confirmed it, though I would expect there to be several serial numbers on an instrument of his, in fact they commonly have different numbers on the ends, reed pans and bellows frames. It would therefore date from the 1850's.
Yes -- as you can see on the pictures there are two numbers (2141 and 1643) stamped on the end, while the number 2032 appears inside. I guess those are some kind of serial number.
Anyway, thanks -- that's been useful. At least I now know where (and when) it came from. Now all I need to do is learn to play it....
Sean