During the spring event, I picked up a couple extra Suishun Mill selection kitsr. I thought I'd sell them at the AD after the event. But, there's a lock icon beside them inventory. No AD button or even a garbage button. I've noticed that Airship selection kit offered in the current Archaeoly event. I have no intention of ever pursuing either prize. So, how long are we spposed to accumulate and hold to this mess? I've no desire to use them, and can neither sell nor delete them. What's up that?