Do you have some reason to believe John is not Ralph's father.

This is the will summary from Frances Coakley's wonderful ManxNoteBook

1789-2 E w CAVEEN Elinor QUAYLE 6 ch thos,john,ralph, 'as also to' cath,elinor + margt creech;some ch ua;husb john

This is possibly will of husband John
CAVEEN, John 1815 Arb E 1 0106417