Syrus and I had been talking about this this morning, and in the past I've tried to get more adamantium to make a suit of armor out of it. I gave up after 3 and a half weeks and getting my official clergy equipment-- the rarity of the material (every nugget I got was from treasure chests) and the worthiness of it wasn't even a consideration after 2 weeks.
I understand not wanting to make +1 armor craftable, but if you were willing to take into account the rarity of the material, give it +1 AC, give it a nice little 10-15% DI vs all physical damage types and push the crafting skill up to 12 or even 14, I think it'd balance out nicely.
It'd /feel/ and /be/ an item of prestige to both the maker and wearer.