In the 0.54 Patch, the bug, making natural leather pants invisible (0021059) has partly been resolved.
This only applies, when the player wearing the pants is rather near.
As soon as the player moves away (approx. 15m), the pants become white again. Giving the same problem as in 0021059.
I would guess that only one LOD has been fixed in the patch.

In addition to this, the natural leather clothing items still have enormous clipping issues with many items as well as lighting issues. {F31201} {F31202}