graeme,
All the information we need about fixing the stone head is here.
http://vernon.qm.qld.gov.au:8080/sea...&highlight=13#
I doubt we could get any of the nut putty here. Would it be acceptable to make up an alternative black putty? Using wax+tree resin or shalac and charcoal dust ?
Finding this site made me look again with a x10 loop. On the inside of the stone a black residue can be found. Also small patches on the wood