I know it's been a while since you posted your message but I wondered if you were still trying to find people with links to your Caines ancestors? If you are, I wonder if you can help me?
My g.grandmother (Gertrude) was a Caines and her father - Robert was born in Staple Hill in 1842. I'm not sure there's a definite connection here, but we've only just started finding out information on the Caines side of my family. My g.grandmother died young and in mysterious circumstances. She lost contact with her family when she married her husband and after she died, he refused to talk about her, even to the children.
I hope you can help me, either with a connection to one of your ancestors or you can point me in the right direction to find out more.