I've received the naturalization records for my great-grandfather with his name spelled incorrectly as Angelo Palmieri and a letter of no-record-found with his name spelled correctly as Angelo Palmeri.
Recently, I sent a request to USCIS asking for a letter of "one and the same". It included all of the documents I have pertaining to him, including his birth and death and naturalization certificates.
Today I received a letter. It states that "we've confirmed that Angelo Palmieri and Angelo Palmeri born on January 27, 1886 are the same person."