THE stonemason at Castle Drogo at Drewsteignton is hoping to find someone who may have worked on the property when it was built between 1910 and 1930.
Wesley Key, who also gives regular tours and talks on the building, wants to know more about the materials used at the time.
'We are trying to find out about the building mortar, particularly where the sand and lime, that was used originally, came from.
'We think the lime may have come from Blackaller Quarry at Drewsteignton and we'd like to find out when the quarry last produced lime and in what form it was sold — quick lime, putty lime or hydrated lime.
'The final piece of the jig-saw is to discover if the stone that was burnt in the kilns was from the quarry or somewhere else.'
Wesley would be delighted to hear from anyone who can help with any information as he is planning some building repair works and would like to use authentic materials if possible.
'Someone may know a person who did work here,' he said.
The castle was designed by Edward Lutyens and is built of granite and oak.
Wesley can be contacted on 01647 433306.