I would hesitate to overdo it. I guess I would attempt building one up using styrene, cut into individual boards. My own attempts at that would inherently have a bit of wiggle and warpage. Add a bit of paint, one board weathered more than it's neighbor, etc. See how that worked, then give it another shot.
We can provide the variation in color and texture pretty easily. I have written a couple of blog posts about how I do so. If you're interested, here are a couple of links: