As far as I know all rights would be owned by Damien and his own label DRM (Damien Rice Music).
I have no idea where you'd get sales figures... do you want album or single sales? What countries?
And "anything to do with production"? I don't understand...
Best source I'd imagine would be to contact DRM. All contact info is here:
http://www.damienrice.com/drmcontact.html