I qualify for jure sanguinis through GGF-GM-M. However, my GGF used many, many variations of his name on official documents:
Italian birth record (1896): Giuseppe Nicola Falco
Marriage license (Kootenai County, ID; 1924): Joe N. Falco
My Grandmother's Birth Certificate (1927): Joseph Falco
Declaration of Intention (1936): Giuseppo Nicolo Falco
Petition for Naturalization (1941): Guiseppo Nicola Falco
Oath of Allegiance (1944): Giuseppo Nicalo Falco
On his Alien Registration Form I received from the USCIS, he states that he entered the US under the name "Guiseppo Nicolo Falo" (missing the "c") and has also used the names "Joseph" and "Joe Falco."
Reading and writing were never Grandpa Joe's strong suits. However, the multiple variations of Giuseppe/Giuseppo/Guiseppo and Nicola/Nicolo/Nicola, along with a few Joes and Josephs sprinkled in will likely make for a difficult explanation at the consulate. Does anybody have any advice on how best to proceed? Are my hopes for dual citizenship dashed? What kind of proof does the consulate require to prove that all of the documents were executed by the same person?
Multiple variations of a name...what to do?
Re: Multiple variations of a name...what to do?
Joe and Joseph are translations of Giuseppe so that should not be a problem at most consulates. The vowel discrepancies on the various documents are minor and, especially on the naturalization records, the date and other pertinent data should make up for the lack of vowel consistency. No guarantees, of course, but I tend to think you will be ok.

