My grandfather died more than 40 years ago without leaving a will. My uncle moved into his house until he died in the 00’s, and my aunt died in 2012 having transferred the house into her name somehow. I imagine this was possible because my uncle had the same name as my grandfather! Now her relatives have put the house up for sale. Does my mother, who is in her 90’s, have any claim on the property?
You and your mother should see a solicitor about this urgently in order to register a potential claim. Since your grandfather died without making a will the property should either have gone to his wife or been divided between his children. One of these, I take it, was your mother. It may take a bit of sorting out, but if the house is reasonably substantial it will be worth investigating further.