Ok I found this document in Gramps’s box of “important” stuff, it’s a member’s letter which elaborates on the organisation of “The first gathering of the clan in modern times”
The organisation is the Clan Hay society who formed in 1951 is a gathering of all old “kin members”, septs of Hay and those desended from family allies by “Bonds of Manrent”
The Hay Clan were one of the most powerful families in all of Normandy from way back to 1000 a.d. Hays owned estates in nearly every county in England.
The society is linked to the Queen and is recognised in the document. The document also mentions that the BBC were also going to attend this first clan gathering.
The gathering was held at Delgatie Castle in Aberdeenshire.
Today on the Clay Hay website it mentions that the name “Haynes” is still currently part of the Clan.