Speak to Xiggs Fuselighter in Ironforge.
I want the rubbings delivered to my tower, but there's no need to have you go all the way there. I'll just have them air-lifted out of Azshara.
Xiggs Fuselighter owes me a favor or two and will be in the area soon--he's signed on to patrol the coast. Speak to him before you leave. He can give you a flare gun to signal him with. When you have the rubbings, just head to wherever he tells you and then give them to him so he can get them to my tower safely. He should be in the hangar in the Military Ward.