[Ger-Poland-Volhynia] Polish Maps

[Frank Schultz]

Hi,

Through one of the links on SGGEE I found a really good road map of Poland. 
My question is: if you zoom in, there are suddenly small numbers that appear in a given village. Those are definitely not distance markers. Could they be house numbers? If so does anybody know whether those would differ from where houses in a given village used to be?
Finally, is there a way to access real estate records in Poland? 
I am researching in the Wyszogrod area and south of Warsaw.

Thanks,
Frank