Hummm….

Having gone and looked at the Wings in question, located at runtimedna.com

Great looking wings and at a terrific price. But the textures appear to be painted rather than actual bird feathers. I'll post 3 feathers I've located.

Perhaps you can make, or get someone to make, a decent bump map from one of these. Then its a matter of baking your own bump map for the wings using Photoshop or similar proggy.

Here's the first...

 Don't sweat the petty things, and don't pet the sweaty things!  ; )