Hello Alex,
this names are not from the Oldenburg area.
I ask the german phone directory and found in Germany only one Medinus address:
Medinus, Erich (0201) 552107
Korthover Weg 21
45307 Essen
This Essen is a big town and located in Westphalia, State Nordrhein-Westfalen.
You should write them!
The directory shows 66 USCHKOREIT, most in Westphalia.
Werner