Here is what the owner of the collection in the picture above has to say about blade play:
Hi Rick, If I understand what they are talking about, when the slimlock is opened all the way there seems to be some play. This is not normal, unless you have a slimlock with aluminum middle liner (blade stop) and if you use the knife over time the aluminum blade stop, would "wear in" with heavy use would cause the gap. 2005 Case used aluminum middle liner and had white fiber side washer on the side of the blade. In 2006 they changed the fiber washer to bronze and I think they changed the middle liner (blade stop) to a harder material. But if the knife has aluminum blade stop, I would look at that to be the problem.
Hope this helps.