Items, NPCs, quests, objects and spells of patch 1.12.1, read live from the realm itself.

Fine Parchment

NPC Level Zone Chance

Dalaran Summoner 34 - 35 Alterac Mountains 0.02%

Elemental Slave 33 - 34 Alterac Mountains 0.014%
Object Zone Chance

Hidden Strongbox Alterac Mountains 34.8%

TWO-SOLUTION TEST 34.8%

NPC	Level	Zone	Chance
Dalaran Summoner	34 - 35	Alterac Mountains	0.02%
Elemental Slave	33 - 34	Alterac Mountains	0.014%

Object	Zone	Chance
Hidden Strongbox	Alterac Mountains	34.8%
TWO-SOLUTION TEST		34.8%