C Man,

I took a quick look at three damascus diamond quality guns and all were similarly marked, "CHARLES DALY EXTRA FINE DAMASCUS DIAMOND QUALITY". The "FINE DAMASCUS" rib inscription is normally associated with Prussian Dalys models of lower embelishment than the "diamond quality" gun.

That said, never say never, but I would expect to see the "extra fine" marking on the rib of a diamond quality gun - along with the "diamond quality" inscription.

Ken