Share '9" resonator cone?'

Hi all, I'm working on an old Resonator guitar at the moment which needs a new cone. I don't work on many resonators, but this particular instrument has a 9" cone which I haven't come across before. I can't seem to source one anywhere! Finding a  9-1/2" is obviuosly not a problem but I'm struggling with a 9".  Can anybody suggest where I might find one of these, or a source for someone that could…