Could it be Ohmstede ?
Omstede is a part of the town Oldenburg. There are four addresses:
Hamm (0441) 17291
Oldenburg Reinhardweg 7
26135 Oldenburg Oldb
Hamm, Dieter Horst u. Hoffmann Maria (0441) 3990304
Oldenburg Ernst-Löwenstein-Str. 20
26125 Oldenburg Oldb
Hamm, Inga (0441) 4851587
Oldenburg Heinrich-Campendonk-Str. 48
26133 Oldenburg Oldb
Hamm, Jan-Dirk (0179) 2078450
Oldenburg Elimarstr. 9
26135 Oldenburg Oldb
No von der Hamm in Germany!