I'm glad I came across this post. I was going to visit the Cemetery in the next couple of weeks, as my 2 x g.grandfather is buried there. However, as it seems it would be impossible just to chance upon his grave, and also I think anyone sharing the grave with him would be his 2nd wife and family, I don't think I'll bother now. My 2 x g.grandmother and baby daughter are buried at All Saints Holbeach, so hopefully I'll have more luck finding their grave.
Lizzie