As you can see in the video clip, reacquiring older Armour Ornaments don't apply once you Unlock them from your Inventory. This is happening for all Ornaments in my Collections other than the ones already seen in the list of applicable Ornaments; which were already available for me from day 1, I did not have to reacquire those. I've tried this on several pieces of armour, not just the Helmet. On a side note: The available ornaments that I have aren't even in my collections. They just exist in my armour's available ornament list.