I recently saw that Jamestown Distributors offers a number of high performance adhesives in their catalog. I've used West system, System Three and 3M 5200, all with great success on various projects. They have a new one, Plexus 310, which is supposed to adhere plastics. Possibly useful for those of you forming the walls of your 'top hats' with plexiglass or lexan. With this adhesive you may not need screws.
John