Hello Earl,
the marriage is recorded in the church register of Asendorf under 1757 # 14b (the "b" indicates that the Marriage was not in Asendorf, maybe in Staffhorst, as you presumed). It is recorded in Asendorf, because Anna Margarethe came from thes parish. The husband spells Harmbr�ck with a-umlaut.
Best regards
Uwe Segelke