Welcome, joelga. A screenwriter, huh? You should feel right at home here. And not a teenager, besides.
Well, you make some good points in your analysis. My Funk & Wagnalls defines "genealogist" as "one who traces or studies the descent of persons or families." The answer I was looking for was Woltz, based on his comment to Hagen, calling him my "Kraut-Mick friend".
The answer to your question, I imagine, would be the priest who baptizes Michael Francis Rizzi.
Next question: He wasn't sure exactly how long he'd been back.