Mum is Sheila Costain and she is going to be absolutely delighted to hear that I have made contact with Gin's family. Persis and Alice (Nan) and the others are all dead, but we keep in touch with Keith's daughter Kathleen and Noel's niece by Marriage Christine Neald in Rhos on Sea. And yes, I remember Marjorie Karran. I only met her when she was in her 80s, but what a character! We don't have any pictures of John Costain and Margaret Quirk, so to get one would be wonderful!! Not sure how we make contact direct - but I think if you go into my tree (Cameron-Costain) and click on my name, you may be able to email me direct rather than through the message board, Do you have a tree on Ancestry that I can try too?
P.S. What is your full name? and are you still in the Liverpool area?