Notes:

Robert Simanton Sr, was a native of Scotland (pg 166 Jacoby) and settled in North New Jersey.
Per records of First Presbyterian Church of Philadelphia, was married May 17, 1738, to Mary McDowell (Penna. Archives, 2nd Series, v.9).
The year they moved to Northampton, PA, is unknown. On July 10, 1775 a deed was conveyed to him of 225 acres, located near Delaware River, signed by attorney for the executors of Thomas Bishop Vickries of British, England. The deed stated that this land adjoined OTHER LAND of Robert Simanton, with point that he came to this county before this date. (pg. 166 Jacoby). Robert was listed on tax list for 1772 for Mt. Bethel, as a farmer. For Jan. 1775, County tax rolls showed Robert owned 225 acres, of which 100 were cleared, 40 sowed with horses, cattle and sheep. (History of Northampton County, Pa., 1877, p.75.

His will dated July 23, 1782 and proved Jan 27 1786. His seven children named: Margaret Nelson, Jane Brittan, Ester Ross, sons: Ephriam, Robert, Peter and Benjamin.
Noted all four of his sons rendered service to the United States during the Revolution.
Source: The Jacoby family genealogy : a record of the descendants of the pioneer, Peter Jacoby of Bucks County, Pennsylvania, 1930 pgs. 166-168 and pg. 173.
Additional information on their children.
Sons; Robert Jr, (FAG # 112626904) and Peter (FAG # 43916882) changed the spelling of their last name to Simington. ( Both Unlinked at this time)
His son John (no memorial) died in the War while being a British prisoner (p. 168, Jacoby).
His son James Simanton (FAG # 19877637)
Margaret (Nelson) and Ester (Ross) have no memorials.

Robert & Mary have no "photo of a formal cemetery burial", many of their family are buried at the old Presbyterian churchyard in Martins Creek.

The Scottish-Irish Presbyterian Cemetery is one of the oldest graveyards in area. The Historic Pennsylvania Society published in June 1899, Old Grave Yards of Northampton by John Eyerman, Pg 5: Lower Mt Bethel Presbyterian, Vol.1 in which he reported the graveyard was in disarray and compiled a list of stones that could be identified. Many of which were a part of this family: Jacoby, Foreman, and Brittan's and some of the Simanton family. Robert Simanton was not listed in that original list, but very conceivable he was buried in this cemetery, in an unmarked grave.
The family bible was lost per his son Robert, Jr, reported on Aug 24, 1837. (Pg 166 Jacoby). Robert Sr will made provisions to be buried in a decent manner at the discretion of his executors. We can infer that his body was buried.

Historical Source: The Jacoby family genealogy : a record of the descendants of the pioneer, Peter Jacoby of Bucks County, Pennsylvania, pgs 166-168; The Simanton family. H. S. Jacoby, 1930.

Buried:
https://www.findagrave.com/memorial/191022572/robert-simanton

Family/Spouse: Mary McDowell. Mary was born in 1713 in Ireland; died in 1784 in Mount Bethel, Northampton County, PA. [Group Sheet] [Family Chart]

1. Jean Simonton was born on 11 Jan 1750 in Bedminster, Somerset County, NJ; died on 8 Mar 1799 in Northampton County, PA; was buried in Scotch-Irish Presbyterian Cemetery, Martins Creek, Northampton County, PA.