i think the reason that my granny has such a weird dialect is because she's been everywhere. She's lived in the south of england, north of england, both east and west and she and my mum lived in Bermumda for a few years. And the she married my grandie, who was a Romani from stockport who also lived in scotland for half his life. So yeah they both have super varied and interesting dialects
(also that's an extremely good film you should watch it)