I would imagine from all that's been written here that it means South Shields is the place for fanny, i.e. the place to get a good shag! I've heard the word 'scut' used as referring to a lady of ill repute. The City Waites do a song called 'Oyster Nan' which refers top her 'itching of her scut'(I'm sure you don't need me to point out which part of her anatomy that is!)
Makes sense to me!