Hi all, mystery solved. I went to Brighton today to visit my father's grave and then on the way back I stopped off at Newhaven. Checked out the address, 3 First Avenue, up for sale. Knocked on the doors either side of the property and at number 1 a couple invited me in, they had owned the property back in the 90's and had rented it out to my mother and her gentleman friend Keith. I now know his surname was Leverton. They last rented it in 1999. The property has since been sold. I was able to find out more information about my mother and Keith which was brilliant. I went armed with some photos I had and the book Mum had written, which the couple Mr and Mrs Miles knew about obviously as the address given in the book was 3 First Avenue. How good is that?
Thanks for your help in this.