I'm the great-great-great grandson of Philander Pratt. My great-great grandparents are Mary Pratt and Charles Bowen.
I can confirm that Philander Pratt and Elizabeth White are buried in an inactive cemetary On Bowmanton Rd. Harwood, Northumberland Ontario Canada, as I reside about 20 mins south of the cemetary. I f you would like further info on the Mary Pratt line please fell free to contact me