I know, the question is 3 years old already, but maybe the information can be useful for somebody in the same situation.
If you tried to rezz a no-copy object and due to some error it didn't appear in-world but DID disappear from inventory, you could think you lost it forever. I had the same problem but as I see now it disappeared only from the local inventory cache in your viewer, not from the Asset Server.
So try to just clear your cache and relog, then force the inventory reloading by typing something in the "filter" field in inventory window and wait - wait util the reloading is finished, it may take a long time (depends on the total objects number there). ONLY AFTER the inventory reloading is finished try to locate your "lost" object in its original place, it should be there. If not sure about the folder, try the "filter" field to find it (but not earlier than the reloading process is over, or you'll get no luck!).
Hope this information will help.