Might I qualify?

[MsKit]

My great-grandfather was born in 1887 in Manhattan New York to Italian-born parents. The 1900 census has his dad listed as "PA" for naturalization status, and then the 1910 census he is listed as "NA" (a citizen). By 1910 my great-grandfather would've been 23, so an adult under Italian law.

I've tried to find naturalization information online to see when exactly his father was naturalized but so far I have been unable to find anything. I understand there are places I need to contact for official records. If those places are also unable to find his naturalization records, would the 1900 census showing his dad as not yet a citizen be enough?

[mler]

There are two major problems here. The first is that the federal government did not keep naturalization records before 1905, which may explain why you cannot find the relevant document. The second problem is that naturalization before 1912 caused the loss of citizenship for all family members, even those born BEFORE the naturalization.

Based on the the information you provided, it seems likely that the naturalization took place before 1905, and extremely likely that it took place before 1912. Thus far, challenges to pre-1912 law have not been successful as far as I know.