I would have bet any money that the Hans Georg GRAFF who accompanied Georg Friedrich KAPP on the 1732 crossing was Georg Friedrich's future father-in-law, but other sources show our subject immigrated in 1695 and founded Groffdale in Lancaster County in 1717.  So… who is the Hans Georg GRAFF who made the passage with the KAPP brothers?  And what is the relationship between our subject and Sebastian GRAFF? 

1.  Item for sale at the web site of the Masthof Bookstore and Press (Morgantown, PA):

1021. Frontiers of Faithfulness—The Story of the Groffdale Mennonite Church by A. Grace Wenger This church history is a story of the Mennonite families who lived in the Groffdale area of Lancaster Co., Pa., throughout the past 275 years.  Named for Hans Graf who came to America in 1695, this story has been effectively recorded by a most capable, retired English teacher, writer, storyteller—now turned historian.  Early families in this area: Bowman, Burkholder, Carpenter, Eby, Groff (Grove), Hoover (Huber), Horst, Landis, Martin, Musselman, Myer, Nagele, Reiff, Sherrick (Shirk), Souder, Stauffer, Summey, and Wenger. (300pp. illus. index. Groffdale Menn. Church, 1992. $20.00)

2.  Leo Schelbert & Sandra Luebkin.  1977.  "Swiss Mennonite Family Names: an Annotated Checklist."  Pennsylvania Folklife XXVI(5): 2-24. Reprinted as pp. 122-144 in Don Yoder, ed.  1981.  Rhineland Emigrants: Lists of German Settlers in Colonial America.  Genealogical Publ. Co., Baltimore, MD (Broderbund CD-267):

p. 131

58. GROFF (Graef, Gráf, Grove). Hans Graf (1661-1746), founded 1717 Groffdale, Lancaster County; 7 sons and 3 daughters; family in Pennsylvania, Illinois, Ontario, and Virginia (ME II-587; MC 139) 1.  Swiss forms: Graf, Graff; widely dispersed, also rural Bernese name (HBLS III-624-626). 2.  Sebástian Graff, with 3 other persons, on the William and Sarah, September 21, 1727; Johann Christoph Groff and Gorg Graff, on the James Goodwill, September 11, 1728 (PGP I-9, 22).

HBLS = Historisch-Biographisches Lexikon der Schweiz; MC = Mennonite Cyclopedic Dictionary; ME = Mennonite Encyclopedia; PGP = Pennsylvania German Pioneers.  Full citations given in the article's bibliography.

3.  H. Frank Eshleman.  1917.  Historic Background and Annals of the Swiss and German Pioneer Settlers of Southeastern Pennsylvania...  (self-published?) Lancaster, PA (reprinted 1969/91 by Genealogical Publ. Co., Baltimore, MD; Broderbund CD-267):

p. 130	1696 -- Hans Graff Arrives in Germantown. The famous Hans graff, one of the founders of the Lancaster County settlement, first appeared in Pennsylvania in 1695 or 1696 and joined the German colony at Germantown.  He remained there for some time and joined the German-Swiss settlement in the neighborhood of Strasburg about 1709. (Lyle's History of Lancaster County, p. 63).
p. 204	1718 -- The First Assessment List. In the first assessment list of Conestoga, which included all of Lancaster County from Strasburg to the River, and as far North as what is now Manheim, the names of the Mennonite families living here in that year (1718) are as follows...
p. 205	Hans Graff, Junr., Hans Graff, Senr...

4.  Israel Daniel Rupp.  1876.  Thirty Thousand Names of German, Swiss, Dutch, French, and Other Immigrants in Pennsylvania from 1727 to 1776.  (republ. 1931, Leipzig; republ. 1965, Genealogical Publ. Co., Baltimore, MD; Broderbund CD-267):

p. 436	No. II SWISS AND GERMAN SETTLERS IN LANCASTER COUNTY FROM 1709 to 1730... 1709... Hans Graff...
p. 437	1719...
p. 438	Hans Graff...
p. 466	The first settlers in Tulpehocken were Lutherans and German Reformed.  Rev. Tobias Wagner was the first pastor of the Lutheran Congregation.  The following is a List of the members of the Tulpehocken Church, from 1743 to 1746... Georg Graf sen., Friederick Kapp, Andreas Kapp... Andreas Graf...
p. 467	Joh. Martin Cass, Geo. Vitus Cass, Joh. Michel Kapp... Johannes Graf... Georg Graf jr...

Is our subject George GRAF Senior?  Are the other three GRAFs his sons?  (Martin and Friederick KAPP are his sons-in-law — "Cass" is an obvious misreading of "Cap.")

5.  Land Records: Bucks and Lancaster Counties, Pennsylvania, 1682-1825 (Broderbund CD-652):

Record ID	Date	Residence	Book-Page	Remarks
41144	28 Mar 1748	Lancaster Co.	B-548	Deed
Property	400 acres in Heidleberg Township
Grantor	Widow Mandoline Groffe
Grantees	Andrew Groff, George Groffe, Hans Groffe, Sebastian Groffe, Leonard Holstein, Barbara Holstein George Emort, Eva Maria Emort Frederick Kapp, Eva Maria Kapp Martin Kapp, Margaret Kapp
Grantee's Wife	Catherine Groffe

If Eva Maria KAPP is Magdalena's daughter, who is Eva Maria EMORT?

6.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).