Not in particular, do I know who Jacob Stifal may be. The IGI seems to locate almost everyone with this (approximate) surname to Wuerttemberg originally (and also, or before that to Switzerland). My immigrant, Hans Adam Stieffel's children, changed their name to "Boots" about the time of their father's death in 1803, in Hardy Co., VA. "Stiefel" means "boot" in German. I too have been unable to find my ancestor in Germany. The one lead some have followed, seen in the IGI, I have just proved false by hiring a German researcher. That Hans Adam Stieffel, born 1733, died in 1747. Mine came to America in 1752. So for us both, back to Square One.