I have GREGER from East-Prussia in my family-tree too!
My father, Egon Arthor Greger was born in East-Prussia in 1939.I was told as a child that the name Gregor was changed to Greger to sound more German during the Purssian War (1870?).In the 1940s, the Greger family was kicked out of (the town name escapes me (I will get it later) East-Prussia during WWII by the Russians.One train went to Siberia, the other to East Germany.My father was fortunate to go to East Germany, where little 5 year old Egon, sister Irmgard and mother later escaped to Western Germany, trading butter along the way. He spend the rest of his childhood and early adulthood growing up in Rupholding, in Baveria.
Egon resides in Whittier, California and has been a resident of the U.S. since 1960.He's still a German citizen.He had three daughters with Lynn Marie Van Natta of San Diego, Diane Marie, 1964, Gina Caroline, 1965 and Erin Nicole, 1969.
Irmgard Andree, sister of Egon A. Greger lives in Neuss, near Duesseldorf.