I think I can help all you out a little:

"Jestem Miliszewski Jerzy z Polski . Nasza rodzina pochodzi z Rajgrodu. Wiem, że nie znasz polskiego. Napisz po angielsku skąd pochodzi Wasza rodzina Jurek"

In English:

I am Jerzy Miliszewski from Poland. Our family comes from Rajgrodu. I understand that you don't know Polish. I'll write where your family comes from in English, Jurek.

I think this might be a bit late to be of any use... but never know. One good deed a day, eh?