I think you are perfectly right, it is not worth wasting time and energy doing anything but getting that certificate. I do not believe in coincidence in these matters and everything points to Charlotte Louie born 1888 in Crewe being grandmother.Incidentally she appears to be in Barton on Irwell in 1911 so she certainly moved around in her earlier years. Even if this is wrong it should be very interesting to know who the 1977 death refers to as there are not that many Kettle entries in BMD. Granny may well have been like many of her generation, 'if somebody else knows all your business they're twice as knowledgeable as you because they know yours and their own'. Probably a lot wiser than today's generation discussing their private affairs on Facebook and having public conversations on their mobiles. Do let us know what you find for although I've found many problems with finding people a death certificate 10 years late with no obvious reason is a new one to bear in mind if it turns it to be the case