From Hans-Hermann's tree...

My Rettke DNA connections at Ancestry tie me and a number of others to Johann Rettke and Wilhelmine Gnadt of Charbrow. See the Radtke DNA Family Tree there for details. See also their daughter Ernestine and her husband August Latal. As of 8 March 2020.

1881 Johann Rettke death certificate, critical document on the DNA collateral line, shared with cousins

Number 25 In Charbrow on 1 August, 1881 Appearing before the civil registrar, it was stated today, by the widow Wilhelmine Rettke, nee Gnadt, who lives in Charbrow, and declared that the herdsman, Johann Rettke, 54 years and 4 months old, of Evangelical religion, who lived in Charbrow and was born in Charbrow and was married, has died. It is announced that he was son of herdsman George Rettke and his wife Constantasia Rettke, nee Bock, of Charbrow and died on the 31^st of July, 1881 at 11:00 a.m.

From Hans-Herman Goebel 8 March 2020 - with thanks. This material is extraordinary.