Found some in Azshara at 68,41 and 63,43

requires 175 lock picking skill.

Your best bet after 180 is Swamp of Sorrows: Pool of Tears.

55, 77
74, 56
66, 49
72, 47
67, 58
55, 78

Those are the ones I know of.

I found one of these on a tiny island at 75,65 off the coast of Azshara, of all places. I don't have lockpicking, so I don't know what it contained. If you want to go take a look, you'll need to avoid a lot of 53-55 (not so tough) elite giants .

Azure Silk Belt is your friend.

These are indeed also found in Azshara, all along the shore line of Southridge Beach.  At LP skill 244, they are still orange.  I will post an edit when they turn green.
Hercene, <Vires Veneratio Iunctum>, Alliance, Zul'jin