An update for anyone who may read this in the future: My husband, the beneficiary, wrote a One and the Same Person Affidavit (just Googled a template). I, the petitioner, and my father, the joint sponsor, wrote one as well. We did NOT notarize them, just typed on the computer, printed, and signed. My father sent us a scanned image of his. I'm not sure if the extra 2 were necessary, but we figured better too much than not enough. This was accepted by the embassy and our visa was successfully processed.