Here is my completed water tower ready for paint (photo 5). I sanded everything with 120-grit, then 220-grit sandpaper to ensure a fairly smooth surface.
I believe that the proportion of the completed tower is off. Next time I will keep the the top of the tower the same size and make the stacks and the base thinner.
Now it's off to the paint shop. I am going to use white “Rust-Oleum, Universal, Advanced Formula, satin paint & primer in one” spray paint that I picked up at the local big-box store. I will spray the tower, then, after letting it dry for a couple of days, will sand or steel-wool it down for a fine finish, then paint it again, until I am satisfied with the overall appearance and finish.