Great job on the shield and fantastic job on the costume!
As for the metal shield, if it were up to me, I'd do it up like it had been well traveled (as in, made a year long trip around the world in various trunks, car boots, vans, etc, but never saw any combat, and someone had found in in their attic after 60 years and sold it to you).
Ding up the pain on the edges, maybe wear the leather down where it's cracking and aged from being folded up funny all those years. You already have one that's "battle damaged", it'd be awesome to have a "USO promotional piece" along side the battle used one.
Again, great job!