Ornate Mithril Shoulder are crafted by Blacksmiths with a skill level of 225.
The plans are a quest reward for completing the quest The Art of the Imbue from Galvan the Ancient in Stranglethorn Vale. This quest is part of the Armorsmith Specialization quest series.
Ornate Mithril Shoulder as a quest objective
This item is an objective of  A Good Head On Your Shouldersω τ ϖ.