The lift linkage seems to be in good shape. This mower has latches that catch when the wings are up, and they do latch properly. When the blades do hit, the wing isn't necessarily at all that steep of an angle down. Mowing with the wing in a "normal" graded ditch will cause the problem. Sometimes....(depending if the blades line up).
You bring up a good point though, I will look the hinges and lift linkage over closer. Maybe something is "tweaked" or worn there I have not yet seen.
Thanks for the reply!