Was Philip's father William Hildreth, mariner? I see that Philip's oldest child was named William. There was a cross-border marriage at Lamberton Toll on 17 Sept 1847 between Anthony Watson Pratt, moulder, to Margaret Ann, daughter of William Hildreth, mariner, both of Tweedmouth. If the Hildreths were nonconformist, then Philip's marriage might also have been a cross-border one, and the records for these are very patchy.
Kath