I got my pair from one of them giant orc brutes. Not sure about everyone else.
The place to look now is by Skara Brea. There is are event gates everywhere. I have found rares off the blackfyre captain, and other red npcs. Supposedy,, you can find stuff from containers in the area, but I have yet to find anything.
There is also a huge Blackfyre dragon spawn to the south. Sometimes an ancient wyrm spawns in its place instead. I tried to solo the thing but it didnt end well. I imagine theres a good chance to fnd something nice off of him.
When there was a baby blackfyre dragon spawning, I could handle that thing easy 1v1. Sometimes it would drop paragon chests, which I assume could have the boots?
I dunno...since I cant open chests, I always give them away fuck iit. If they unlock it and get something that makes them happy, then I'm happy