This patch made adjustments to the The Final Respite which is the Halloween back item and backpack. One was so it could be used as a backpack to store stuff and the other was so it lost the unique tag.
Although now there are no UPHs around near as I can see so unless they respawn them unique tag or not we're still only going to have one each. Unless we buy the replica version from the new items shop that is.
As for making old ones into usable backpacks for storage use a screwdriver on it.
You combined "Screwdriver" with "The Final Respite" and the result is a quality level 1 "The Final Respite Backpack".
The screwdriver is used up and it should be usable as a backpack now as the name suggests. Although when I right click on it it doesn't open. I just get the items locked error message since my back slot is locked in my clothing tab and right clicking it tried to equip it rather than open it.