My wife's greatgrandfather is Frederich Gentz b.21 Apr 1847 in Mecklenburg Schwerin. He must have moved to The States as young man for he married to Caroline Fritsche. His father is Christian Gentz b.7 Jul 1823 to Fredricka Bell. His father is John Gens. They used the names Gentz, Jens, Gens, etc interchangeably it seemed. They finally settled on Janzen which has been used for the last 3 generations. I hope we can make some connections. One suggestion: you might try photographing your father's papers. Digital is fine. I find that I can blow up a digital photograph when the text becomes dificult to read.