While you no longer need to complete the Mithril Order chain to access Imperial Plate, it’s still the only way to get the Ornate Mithril plans. So if your a completist like me, then you’ll want to do this chain. You need to be level 40 and level 200 Blacksmithing to start this quest chain.

The chain starts in Orgrimmar for Horde and Stormwind for Alliance.

Horde
http://www.wowhead.com/?quest=2757

Alliance
http://www.wowhead.com/?quest=2759

McGavan is outside the Blacksmiths in Booty Bay.

McGavan then sends you to find Galvan the Ancient in Stranglethorn Vale.
http://www.wowhead.com/?quest=2760 (map for Galvan’s location here: http://www.wowhead.com/?npc=7802)

You’ll now open up the Mithril Order quest chain.

Quest #1
Smelt On, Smelt Off - http://www.wowhead.com/?quest=2761

Bring Galvan the following:
40 x Iron Bars
40 x Mithril Bars

You will get Plans: Ornate Mithril Pants as a reward.

Quest #2
The Great Silver Deceiver - http://www.wowhead.com/?quest=2762

Bring Galvan the following:
40 x Mithril Bars
5 x Truesilver Bars

You will get Plans: Ornate Mithril Gloves as a reward.

Quest #3
The Art of the Imbue - http://www.wowhead.com/?quest=2763

Bring Galvan the following:
40 x Mithril Bars
4 x Citrine

You will get Plans: Ornate Mithril Shoulder as a reward.

Quest #4
Expert Blacksmith! - http://www.wowhead.com/?quest=2765

Just talk to Galvan and claim your reward.

Quest #5
Galvan’s Finest Pupil - http://www.wowhead.com/?quest=2764

Galvan now sends you to Gadgetzan to find Trenton Lighthammer. He is on the south side of Gadgetzan by the forge and anvil. He is the Night Elf, you cant miss him.

Trenton will now give you and another series of quests.

Quest #1
The World At Your Feet - http://www.wowhead.com/?quest=2772

You need to make the following:
Heavy Mithril Boots (14 x Mithril Bars, 4 x Thick Leather) x 2
Ornate Mithril Pants (12 x Mithril Bars, 1 x Truesilver Bar, 1 Solid Grinding Stone) x 1

Total materials needed:
40 x Mithril Bars
8 x Thick Leather
1 x Truesilver Bar
4 x Solid Stone

Trenton will now teach you how to make Ornate Mithril Boots.

Quest #2
The Mithril Kid - http://www.wowhead.com/?quest=2773

You need to make the following:
Heavy Mithril Breastplate (16 x Mithril Bars) x 2
Ornate Mithril Gloves (10 x Mithril Bars, 6 x Mageweave Cloth, 1 x Truesilver Bar, 1 x Solid Grinding Stone) x 1

Total materials needed:
42 x Mithril Bars
6 x Mageweave Cloth
1 x Truesilver Bar
4 x Solid Stone

Trenton will now teach you how to make Ornate Mithril Breastplate.

Quest #3
A Good Head On Your Shoulders - http://www.wowhead.com/?quest=2771

You need to make the following:
Mithril Coif (10 x Mithril Bars, 6 x Mageweave Cloth) x 2
Ornate Mithril Shoulder (12 x Mithril Bars, 1 x Truesilver Bar, 6 x Thick Leather) x 1

Total materials needed:
32 x Mithril Bars
12 x Mageweave Cloth
1 x Truesilver Bar
6 x Thick Leather

Trenton will now teach you how to make Ornate Mithril Helm.

Quest #4
Did You Lose This? - http://www.wowhead.com/?quest=3321

Just talk to him to get your reward.

Your now done with the Mithril Order quest chain.

So in total you’ll need the following materials for the entire quest chain:

234 x Mithril Bars
40 x Iron Bars
8 x Truesilver Bars
4 x Citrine
14 x Thick Leather
8 x Solid Stone
18 x Mageweave Cloth