I am trying to find more information about Hans Heinrich Rudolf Oldag and Ernestine Pauline Friederike Hampel, the parents of Anna Minna Martha Oldag (born 10 Oct 1866 in Warmbrunn, Silesia, now Cieplice Śląskie, Poland).
In particular, I am trying to establish whether he was born in Techin, Lauenburg, in September 1828. It seems a long distance to travel.
I know that the parents of Anna Oldag died within a short time of each other (possibly on the same day, but most likely no more than a week apart) some time between 1868 and 1875.
I am hoping that there might still a marriage record, or death records, or perhaps grave markers in Poland. Short of traveling there myself, what other resources might there be?