Use a flie recovery program to find places.sqlite (history & bookmarks), history.dat (history), localstore.rdf (toolbars), sessionstore.js (session) and sessionstore.bak (session).
To attempt to recover Firefox history, use ff3hr. In order to use this program you will first need to make a disk clone.
Cache files are completely useless. A cache is some downloaded files that are stores on your computer the first time you visit a website in anticipation of possible very-slightly-faster loading on future visits.
I am absolutely amazed that with everyone professing high levels of computer knowledge, no one knows which Firefox files are relevant and no one has told you to ignore the damn cache file.
