EK1 Iron Cross / Eisernes Kreuz 24 AdHP in a case Robert Koch is a jeweler from Frankfurt & Main

AdHP im Etui Robert Koch ist ein Juwelier aus Frankfurt & Main

These pieces can be linked to Robert Koch jeweler a certain he was lives the Frankfurt & Main.
So far only unmarked pieces have been found, but always with the same associated box.
Typical and the shape and soldering of the hook are also unique features
These pieces are not easy to find, as they were not made in series production by a larger company, but were assembled in small numbers from parts purchased from a work community.