After you gave Wuuthrad back to Ysgramor his statue, you can pick it up later.
But would that be honorable for a Nord? To take his weapon?
I kind of want it for my character, who is very gloomy and dark, but heroic and kindhearted.
That face on the axe screams for: ''I bring you agony.''
Seems like a nice thing for my character.
However, she is also very respectfull about Norse culture, and taking the weapon from one of the greatest Norse heroes might be dishonoring in her eyes. She might prefer to keep the weapon at rest together with Ysgramor in his tomb.
I can always make a Nordic battleaxe, the black fur and the patterns has a pretty dark atmosphere aswell.
Or maybe an ebony battleaxe.