Here is a side-rear view of the oak water tank.  This actually came out better than I expected...  ;- )  There is a lot more "staining" running down the side from overspill of the filler pipe on top but it does not show up well in the photo.  The small floor in front of the tank is to prevent spillage from creating a mud bog.  The rusty old bucket is to catch the constant drip from the downspout as the old valve just doesn't seal like it did when it was new...