My line includes 3 generations of Olthof's coming from the region justsouth of Leer Germany...towns like Amdorf, Collinghorst, Loga, Glansdorf.
Roots go back to the early 1700's
AND...there is a line of Olthoff's that stretch to the 1520's that I hopefully will tie into someday....they are over by Ditzum on the west bank of the Ems.
Looking for more info on Reent Haten Olthof5/1724-8/1784 and his wife Thalke Hinderichs 1719-1794
The last generation listed switched the records to Althoff.
Hope to hear from someone!