The mount bracket is two flat vinyl boards glued together and then attached to PVC fixture from back-pack harness.
Found the missile launcher mounts at Lowe's at a discount, they are PVC deck railing brackets from a mismatched opened package.
The launchers themselves with missiles will be easy to make from PVC and vinyl pieces.
The missiles will not fire of course, just for looks, but would be cool if did like a Nerf gun or something.
I found some cheap plastic funnels in various sizes at Harbor Freight that I will use for the missile cone-tips.