You don't think the location starts with W? It looks like the first letter in Winiarz.
You have not located Andrzej's arrival manifest? That would be the cheapest.
Yes, the SS-5Form costs [$27] and you do need to have his Death Certificate.
I would think the Naturalization Intent & Petition would be the cheapest.
Is this your Andrew's Draft Registration?
Name Andrew Gill
Event Type Draft Registration
Event Date 1917-1918
Event Place Buffalo City no 7, New York, United States
Birth Date 16 Nov 1888
Birthplace Januf, Warsaw, Russ Poland
Warsaw was a name of gubernia to identify the location "Januf" Janow's location.
Warszawa is in Mazowieckie wojewodztwo so than Janow should be in that same wojewodztwo. I'm listing several:
gmina Mińsk Mazowiecki