Theobald Gerst and his wife Magdalena Catherina arrived in Philadelphia on 11 Aug 1750 on the ship "Patience", with all of their children except John Nicholas, who had arrived in 1749, and whom they joined in Bethel twp, Lancaster Co, PA. There is a web page for the ship passenger lists at <http://www.execpc.com/~trarbach/Patience/1750Patience.html>
, and a web page for Garst/Gerst Genealogy at <http://www.garstfamily.com/>
This family is profiled in William T. Garst's "Our Garst Family in America", pp.15-16. Mr. Garst's sources for this family were the Pennsylvania Archives (passenger lists), and Theobald Gerst's will, dated 22 Apr 1770 (Lancaster Co., PA will book A, Vol 1, page 245), entered probate 13 June 1770. The will lists his wife Magdalena Catherina, sons John Nickel and Theobald, and his daughters Engelina, Magdalena, Catherina, Margaretha, and Elisabeth.
The Kirchenbuch of the Evangelical Reformed Church of Sembach, Pfalz, Bayern (Bavaria), LDS FHL microfilm #193169, extracted into the IGI as batches C/M997251, records on p. 51B, the marriage of Theobald Gerst, son of Michael Gerst, to Catherina Bückin, daughter of Johannes Bück. (Bückin is indexed as Bueckin in the IGI.)
I have examined this microfilm. All birth and christening dates for the children of Theobald and Catherina are from it. I list in the child's Notes only the page and the way the names were entered. (The original pages are numbered only on the upper right of each pair of facing pages. I have appended A to refer to the lefthand page and B for the righthand page.) All the christening records also list godparents, most of whom I have not entered into my notes (the German text is hard to read.) Sembach (now spelled Sambach) is a village about 6 km southwest of Bamberg.
The IGI also indexes a 3-page family group record for Theobald Gerst & Magdelena Catharina Bueckin, in batch 5001681 (pages 42 through 44), on LDS FHL microfilm #1396477, submitted by Betty Farnsworth, 10315 South 1540 West, Jordan, UT 84065. She, in turn, seems to have relied heavily on the IGI extractions cited above, but apparently did not go to the original as her submission does not include birth dates or the fathers of Theobald & Catherina. Her family group record is my source for the birth of Theobald Gerst in 1702 in Schwenkhausen. I do not know her source for this place of birth, and considering that it does not have any more than the same year that William T. Garst used in his guestimate, it does not seem too likely that she found a birth record. The IGI for Germany does not list any extraction record for Theobald's birth.
Her full name was actually Maria Magdalena Catharina Bückin, but if I were to put that, the software would abbreviate it to Maria M. C. Bückin in charts with limited name lengths, which would be confusing since she was known as either Magdalena Catherina or just Catharina (see baptismal records of her children.)
Also, the "in" in "Bückin" is the feminine surname ending. In modern naming conventions we would call her surname just "Bück", which is usually Americanized to Beck. Some researchers have misunderstood this convention, and mistakenly published her father's name as Johannes Bückin.