Relevant text from Henry Winter letter to William Zuill, March 23, 1936:
"...although I believe that Philip Dunscombe's wife's name was White, at least he is mentioned in the will of Matthew White as "my son Philip Dunscombe." I have unfortunately lost this reference, but will look it up again to confirm it..."
This conforms with the fact that Phillip received a bequest in the will of "brother" Rev. Nathaniel White.