I've had copies of the .72, .73, .73 (dev) and .74 releases and almost deleted the main one where all the maps were stored during some cleaning up. Well almost, I'm not so trigger happy when it comes to deleting important stuff anymore.
Dude, get an undeleter (like norton system works). 'Deleted' files are simple delisted from your systems file explorer. THey're not actually wiped for some time.