While Blind's idea is cool, it again starts to diverge from it being a grille design.
Personally I'm not a big fan of the wings; both the shape and the fact that I feel like they make it more of a "Warchicken" than "warhound"

The consensus I'm getting is that the cogs are the most appropriate. Which I'm starting to agree with, especially since I'm not gluing onto the armour any of the optional Admech icons that come with the Warhound kit.
So I threw this together:

The cog has been made a bit chunkier so that it will rout out nicely. What I figured I can do with the circle inside the cog is mount it using a piece of really thin wire glued behind it and to the rest of the grille. It would be visible but only as a very fine fret. I expect this would be the way that signs and things in real life are done.
One further option with the gear design would be to add a skull in the centre instead of a circle. Because the skull would be positive I can cut out the eyes as holes:

I think this might be the way to go...
Oh yeah I can make that....