Hello.
Coldewey is at 53 degrees North 19 minutes East by 8 24 East in Lower Saxony, about halfway between Oldenburg and Bremerhaven. There are also towns named Coldewei.
The nearest Hohenkirchen is at 53 40 N 7 56E, near Cuxhaven. I can't find a place named Ollacker or similar.
Sincerely yours,
Henry Heinzmann