Medieval Cart Collection - Need Help Please


I’ve begun to create a small collection as part of a larger project. I’m developing a series of carts and I thought I was at the place to begin asking for help. My collection will include a small “market cart” which is a hand-pushed cart, a small horse-drawn cart and a four-wheeled horse drawn wagon (the last of which I have not begun yet.

Here’s what I’ve got so far:
This is the handcart

Here’s the small horse-drawn cart.

Here’s some problems: I stink at materials and textures. I was going for a simple wood texture. Given the modeling of the horse-drawn cart I think the very subtle texture works fine, except for the wheel, which looks awful.

Any criticisms? Suggestions? Hints on how to get these things ready for animation?
I’d appreciate any comments. Thanks!