The mystery of Isaac Shinn's parentage

In September of 1902, my great grandfather received a letter from Josiah H Shinn stating that he was writing a book about the Shinn family.

The letter asked for any genealogical information that he could provide (names, birth dates, etc...) to be included in the book so that future generations of Shinn's will be able to learn their heritage. 

Unfortunately, my ancestor never responded to the letter and my family was left out of the book that would later be titled, "The History of the Shinn Family in Europe and America".  This is why I call them the "lost" Shinn family.  The church that my Shinn ancestors were baptized in, burned with all of the records.  There was no family bible.  And to make matters worse, the cemetery that my 3rd great grandfather was buried in is now gone.

My 3rd great grandfather was Isaac Shinn.  
He was born somewhere between 1800-1806 in Vincentown, NJ
He married Mary Dick around 1828
It was said that either he or his father was a Quaker and was disowned from the Church.

Family lore says that he was baptized at the Church of Evangelist
near Crosswicks, NJ, but I have not found any records.

Between 1818 and 1824 he was a member of Old St. George
Methodist Episcopal Church in Philadelphia.  These records are available on www.ancestry.com.

He was a shoemaker by trade and lived in Philadelphia most of his life.  Isaac and Mary supposedly had 12 children, but only nine of them survived.  Their children were...

Isaac Shinn (1830- ?)  married Jane
Francis Marion Shinn (1832-1907) married Emma Nicholls
Mary Carmaliza Shinn (1838-1904) married Jeremiah Seeger
Charles T Shinn (1839-1890) married Mary Bunting
George W Shinn (1840-1910) married Sarah/Sallie Frame
Edwin Forrest Shinn (1842-1918) married Susan Faries
Louisa A Shinn (1845-1907) married Henry Bobb
John D Shinn (1848-1900) married Elizabeth Clark
Anna Shinn (1850-1900) married William Warburton

According to his obituary, Isaac Shinn died at the age of 60 on July 11th, 1868. 

He was buried in Philanthropic Cemetery in Philadelphia.  This cemetery is no longer around.  The bodies had all been moved to Arlington Cemetery in Drexel Hill in common burial boxes with no records attached.

I have exhausted every resource that might give me a clue as to who his parents were.  I do have several possiblities in mind, but no proof of relationship.  I am hoping that someone out there may be able to help.