From here, that top looks a bit like a viol top, sometimes made from bent planks fitted together. So I guess it could be made from a harpsichord soundboard.
Incidentally my godfather is Andrea Goble of Robert Goble and Sons in England
http://www.gobleharpsichords.co.uk/index.html
When I was there a few years ago I was shown some very nice instruments ... and some LOGS of ebony!