The game's collection data lists Rot-Proof Greatplate as sold by a vendor NPC in Stormshield.
Vendor
Zone
Map
Waypoint
Other items it sells
NPC #93907
Stormshield
-
-
171
Vendor NPC, zone and position come from the client's collection source tables (CollectableSourceInfo and CollectableSourceVendorSparse); coordinates are the in-game map readout.
Build history
First seen in build 5.5.4.69585 (Mists of Pandaria).
Read from the World of Warcraft client build files.
How Rot-Proof Greatplate Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Rot-Proof Greatplate suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
4 other items in the current build are also called Rot-Proof Greatplate. Same-name entries are usually a different rank, faction, quest stage or reward track of the same object.
Blizzard numbers items as they are created, so the named items next to ID 96075 (96070 to 96080) were usually added in the same batch as Rot-Proof Greatplate: the same quest line, zone, vendor or reward set.