Guenther lived in Beuthen at Ring 11 when he married, and the record of the annulment of his German nationality gives the same address. Other people whose annulment cards show the same address are:
- his wife, Lotte,
- Heinz born in Beuthen on 03/03/1925,
- Fritz, assumed to be his son, in Beuthen on 18/04/1929.

Guenther's WWI service record identifies his parents as Heimann Gruenpeter and Anna geb. Gruenpeter, also at Ring 11.