Kev I think you need to start with your parents marriage cert and work back ,and then we can all help you ,there is no rush we ,know your dads date of birth and who his parents were ,I know certs arent cheap but they will save a lot of researching the wrong family,can you not access any family details ,someone in your family may have official documents stored away ,ask around and take notes,listen to what your family say ,and get back to us ,we can and will help you,its just you seem confused over dates,
Gillian