A quick alternative would be to start a new game based on the module, head to the missing map and select the map layer, click the map, press Z and right click>save the resulting popup. You'd they have to upload it to your library to add it back to the original game until you were able to get it restored via other means. You can always delete it from your library once you are done with it or have the original back :) edit: bah, sniped!