Ok, take some scrap wood and run it through an old cloth between your fingers with brown/black paint on it to stain the wood to varying degrees. The cylinder is a used 35mm film container cut down. The roof a circle of stiff card file cut in a circle, slice out a wedge and glue together. Hide seam with wood trim. Shirt pin on peak. Used thread waxed for bands. The turnbuckles are grandt line (yup, you gotta buy 'em!) Water tubes underneath are straws, stirrers, whatever.

Drill several holes in small brass tubing & work into a slot. Cut off the section of tubing - voila! It is a turnbuckle. You could also use half a round toothpick, carved to fit over the tank hoops, or just blob on some epoxy glue, or wrap the hoops in paper.]