It may boil down to a judgment call, but I think you also need to consider the credibility of the records you found. Census records, for example, are notorious for misspellings, since an enumerator often just wrote what he thought he heard. Copies of original birth, death , or marriage certificates are usually pretty accurate; and draft registration certificates are good, because they were normally completed by the subject himself, who presumably knew how to spell his own name. But transcriptions of old handwritten records may be subject to interpretation, so if any candidate spellings are based on those, it's best to try to find the original document and make sure you agree with the transcriber.