Super Excellent Royal Piece!
Clam Shell has prince Richard's Royal Crest.
Inscription says "Gewidmet von Fursten Richard von Wittgenstein Berlebung"
which means "Dedicated to Prince Richard of Wittgenstein Berlebung"

Prince Richard Casimir Karl August Robert Konstantin is the eldest son of Gustav Albrecht,
5th Prince of Sayn-Wittgenstein-Berleburg, a highly decorated Nazi officer declared missing in 1944 yet only legally declared dead in 1969.
Richard was raised in Sweden with his maternal grandfather,
 the Duke of Otrante, at Elghammar Castle.
He attended the boarding schools Viggbyholm and Sigtuna.
Having studied forest science at Munich University,
Prince Richard obtained his forestry diploma at the University of Göttingen in Hann.-Münden.
He took his post-graduate training as Forstreferendar, obtaining a degree as
Assessor des Forstdienstes after passing the second forestry examination
 at the North Rhine Westphalian State Forestry Service.