[Ger-Poland-Volhynia] Russian, German, Polish puzzle

[Charlotte Gorley]

I'm enjoying the thread about Russian/German/Polish clarity very much.
 
In researching my ancestors (Bierwagens and Garbes) I've come across the
'blurring of border' issue.  When they came to Canada, their home country is
listed as Russia, yet I have found evidence that they lived in Kurowek,
which is in today's Poland.
 
I've heard accounts that they lived within a couple of miles of the border
while they were there and would dearly love to find out more about their
history.  
 
Has anyone come across the surname Bierwagen or Garbe?
 
Charlotte