Thank you very much Pete I knew it was a general grave - the lady from the Council who gave me the details actually did call it a pauper's grave - so I knew it would be a patch of grass rather than a headstone.
Yes you have the correct grave for Francis Louis Longford who was my grandmother's first husband, whose death I have only recently discovered. His death certificate says he was a street musician, and he was 87 years old when he died so sometime I hope to check for any entries in newspapers to see if he was a bit of a vagrant.
As I am in Merseyside I have no idea when I am likely to visit Sussex but when I do one day I will be able to visit the cemetery and thanks to you, locate just where the grave is.
Thank you Toni for your lovely offer, but unless you were going for yourself then I wouldn't put you to any trouble since the link to "Where's the Path" from Pete is excellent, I haven't come across this before.
If I can help with anything for you in Lancashire/Merseyside, don't forget to give me a shout - one good turn always deserves another

Mary