A few days ago, while the weather was cooperating, I painted the pieces for the styrene Octagon Port. Here are the pieces all laid out (minus the center round piece).
I wasn't sure how well a hot glue gun would work on a plastic but I gave it a try. Long story short, it worked nicely....the only caveat is the stringy-residue that a glue gun can create. Just go slow and evenly, keeping that tip off the plastic material.