thank you for the information. I was not aware that this was a custom in Radzionków (or Silesia, for that matter). I had assumed that REDER was an alias given by e.g. his stepfather. This clears it up.
While Radzionków is the most likely place of marriage, I would also consider Piekary or Kochłowice as possible places. There must be some connection between that American DNA match and us.
Greetings from Copenhagen,