This could mean that he was born in Vilnius (Wilnius,Wilno,possibly Wilnov in Russian),capital of Lithuania,which in 1893 was still part of the Russian Empire. According to this reference,the city comprised a significant Polish community during that era,which could account for the ethnic origin of your grandfather's patronymic.http://en.wikipedia.org/wiki/Vilnius
Just a suggestion,of course - this isn't my field,but my youngest brother has a PhD in Slavic Studies from IU,so I've learned how to think about these things from him. And of course Wiki is open-source,thus not totally reliable.
I do hope this helps somehow - btw,I found your post accidentally during a search of that family name.