You wanted to take a quick look at last firefox tab state on browser which isn't stared any more? You want to restore session state from some other profile (from other computer perhaps?).
Firefox stores session data (including back history!) in .mozilla/firefox/po0qgwdl.default/sessionstore.js and you can use html page generation javascript from ZeePrime@mozillaZine forums.
For easy access I re-idented it here. Thanks, ZeePrime, very useful.