↑ 1.01.11.2 Lower Skippack Mennonite Cemetery, Skippack, Montgomery County, Pennsylvania, USA, in Find A Grave.
'Johannes Detweiler, Jr Birth: Aug. 24, 1721 Montgomery County, Pennsylvania, USA Death: Dec. 9, 1806 Montgomery County, Pennsylvania, USA' 'The will of John Detwylar (sic), Skippack Twp. Montgomery Co ., is dated 1801 and proved 18 December 1806.' From a photo of the gravestone (which appears to be quite new): 'Detwiler: Johannes Aug 4 1721 - Dec 19 1806'
The dates on the gravestone (especially the death date) are suspect, as his will was proved 18 Dec 1806.
'Anna Reiff [daughter of Abraham and Barbara (Meyer) Reiff], b. 7 Jan 1723. She died 9 Jan 1798 at Skippach Township, Montgomery County. She married John Detweiler of Skippack, Montgomery County in about 1743.'