If anyone has the names of his brother, sister and mum it would be a great help.
You should see if anyone from Urbański family from city/near Toruń is registered at nasza-klasa.pl
. This site is the most popular website in Poland and almost everyone - mainly Polish people, are registered over there.
They have a forum where you can post some questions.
his father was called Josef Urbański.Josef
in Polish is spelled Józef
just in case you need it.