I know this doesn' t really help you,
But since everything in SL is just an entry in a stonking big database, they is no damn excuse for LL to ever allow "Inventory Loss" to happen. In any good database you do not delete items, you mark them as not active, so that after a suitable period, say a year you can archive them and then delete them.
Imagine if your bank suddenly lost all records of your deposits. There is no difference between your bank records ands items in SL. They are both at the computer end, just a bit stream.