Well you certainly seem to have a problem with the Payne family. I have been looking for anything to help but it is always exceedingly difficult when you have very little info to go on.
However, I did find a marriage for
Ralph William Payne and Norah Elizabeth Young, 11 Feb 1929 in Calcutta, Bengal, India. The father of the groom is given as Arnold Walter Payne. You may already have found it but if not it is in familysearch.org.
You said you have Guy's marriage cert, does it mention if the father is deceased? Does any family member know if Walter was born in UK? Do you have any old pics with notes on the back?
I cannot find the death cert for Guy in 2006, do you know for certain it was Nottingham. As I live in Derbyshire it would be interesting to know where exactly he died. Was Sissy short for another name and did she marry in UK or abroad? If you can come up with any other details it will help.