Maternal relationship is confirmed with an AncestryDNA test match between Peter Cobcroft and Gwen Cobcroft (Holmes). Predicted relationship reported by AncestryDNA: Parent, Child - immediate family member based on sharing 3,469 centimorgans shared across 68 segments; Confidence: Extremely High.
Paternal relationship confirmed with an AncestryDNA test match between Peter Cobcroft and a second cousin who is not a Wikitree user - descendant of James Carlton Cobcroft's daughter Myrtle Phillipa Harris Cobcroft. Predicted relationship reported by AncestryDNA: 3rd Cousins based on sharing 166 centimorgans shared across 11 DNA segments; Confidence: Extremely High.
Paternal relationship is confirmed through Y-chromosome FTDNA testing. Peter Cobcroft and Alan Cobcroft supporting their direct paternal lines back to their MRCA John Cobcroft.
It may be possible to confirm family relationships by comparing test results with Peter or other carriers of his ancestors' Y-chromosome or mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree: