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.
Best luck!