Simon Jacob's descendants used the last name Simon. His son Jakob Jehuda Simon is buried in Hechingen. His daughters married into the Froehlich family of Rexingen.
I think that some of the Mayer descendants were the Guggenheimer family, but I have not proven that yet. There was a Mayer Guggenheimer who lived in Hechingen at that time, but I am not sure if it is him. I know some of Mayer's decendants took the name Mayer because his grandson was Rabbi Dr. Samuel Mayer (1807-1885).
One of Mayer's daughters married into the Loewengard family of Rexingen. One of his sons married into the Auerbach(er) family of Nordstetten.
Ralph N. Baer is researching the Arnold and Dreyfuss families in Hechingen. The Dreyfuss family married into the Pressburger family of Rexingen.
Simon Jacob may have been from Ederheim, Schwaben.
Pinkas Hakehillot: Germany: Wuerttemberg, Hohenzollern, Baden edited by Joseph Walk. Published in 1986 by Yad Vashem. 549 pages. (This book is an encyclopedia of Jewish Communities in Germany. It is one volume of a larger set.) This book is entirely in Hebrew, but it has an English Table of Contents. It is available through Yad Vashem. The community of Hechingen is discussed on pages 171-174.
Juden in Hechingen by Casimir Bumiller. This book is in German. I saw it at the NY Public Library and have wanted to purchase it ever since. It is a short book (70 pages) commenting on various aspects of the Jewish community.
Die Juden in Hechingen als religiöse Gemeinde by Manuel Werner. This is a long article from the German Periodical. I Xeroxed it at the NY Public library and never wrote down the name of the periodical. However, I think it is from Zeitschrift Für Hohenzollerische Geschichte.
Die jüdische Gemeinde Hechingen im 16. Jahrhundert by. Casimir Bumiller. In Zeitschrift Für Hohenzollerische Geschichte pp. 159-184. 1988/89.
If you have any information about the jewish community in this town or have ancestors with the same surname, please contact me.
