I am looking for information about the Rubinstein or Friedman families from
the following cities in the former East Prussia:

Loetzen (Gizycko - Poland)
Insterburg (Chernyakhovsk - Russia)
Schirwindt (Kutuzovo Russia)
Darkehmen (Ozersk - Russia)
Rastenburg (Ketrzyn -Poland)
Gerdauen (Zheleznodorozhny - Russia)
Treuburg (Olecko -Poland)
Mierunsken (Mieruniszki/Merunen -Poland)
Orlowen (Orlowo - Poland)

Can anyone help me?

Also researching the following surnames:
RUBINSTEIN, FRIEDMAN, KATZ, BOLDER, DOBRIN, WITTENBERG, GUTMANN, LAX,
NATHANSON, LOEWENSTEIN, SALINGER, TROPKE.

Janus Koester
Denmark