Currently, none of the level 60 pvp gear is eligible for Transmogrification. However, it looks like it's http://us.battle.net/wow/en/forum/topic/3657275742?page=9#178 being worked on . To be able to transmogrify the replica of this item, you'll need to purchase the newer items from https://vanillawowdb.com/?npc=58152"">(NPC #58152) in Area 52.

Please be aware that you need to have the ?achievement=449"">(Achievement #449) Feat of Strength (or higher rank) to purchase this item!