I fastened the Z-brackets to the spar.
Next, I cleccoed the baffle and ribs over the Z-brackets.
Finally, I cleccoed the tank skin to the ribs. I this image, you can see the space between the tank skin and the main skin. It’s important to minimize this gap as much as possible. I should be able to reduce this gap by pulling everything tight during the assembly process. 
Here’s the cleccoed left wing. Looking good!
