Evening Sue
I am researching the Cretney family and have a record of David Cretney baptised on 29th May 1796 at St Georges Church Douglas Isle of Man.
His parents were David C b 1753 and his first wife Ann Cottier married 1780.
I have no record of your David's future to Liverpool or any subsequent information of a David on the Island.
Sorry its not much help but if you want any older history of the family I can give you more if you have not already got it.
Allan C