Thank you for your response. The only other naturalization record I have for my great grandmother is a copy of her petition for naturalization, which I received from NARA, together with the certificate of arrival. The arrival info on the petition matches perfectly with the arrival info on the certificate -- with the added detail on the petition that she embarked on the ship in Hamburg.
I have taken one further step. I just ordered from U.S. Citizenship and Immigration Services a copy of my great grandmother's consolidated "C-File," which should include additional naturalization documents, like a declaration of intention to naturalize (if she filed one).