all of your axis locks have vertical play?!? damn... the way it's designed it really shouldn't get any. I have a mini grip that is completely solid vertical, little bit of side to side. I have a brand new delica that has more vertical play.
Does the axis lock stud thingie move back and forth when you are getting this vertical play? This is a design that should self adjust for any stop pin wear by the springs putting tension on the axis lock to close the gap. The blade gets sandwiched between the lock and the pin... wish i could be more helpful