Guild Wars 2

So, I acquired “There with Yakkington: Traveler’s tale” ascended back item prior to patch, knowing I’d get to change the stats on it. Thus it now has celestial stat set. Question came up however whether I’d be able to upgrade the item with the upgrade recipe of Yakkington’s, and more importantly, what happens to the stats?

First i would say that you should take it to the forge and confirm weather it can go in. I would be very surprised if it can’t.
I assume that you would be able to make the infused version and once you create it you would have to pick the stats again.