I see it time and time again. Blast white slds in problem-free slabs. It is my understanding that slds were NOT stored in vaults like morgans. So it's a fair assumption that they should have some tarnish. Yet I keep seeing these dipped/cleaned coins come up for auction every month in problem- free slabs. I understand why they might be alluring to newbies used to collecting Morgans but slds have a much different history. What's the deal?