A few days ago, I cut a small piano type hinge and attached it to a piece of scrap acrylic which was then glued to the curved door I made for bender. Add a few scrap pieces of angle iron and girders from the vex kit and and after about a dozen experiments, the door was hanging on Bender. It opened and closed better than my expectations. That was the hardest part of the project so far.
After the door was attached, I reinforced the wooden 2x2's (that ringed the torso) with drywall screws. Once those were in place it was an easy task to cut styrene and attach to the body. The work will be when I start filling in the cracks and seaming the joints together with bondo and sandpaper. The only problem I haven't worked out yet is how to permanently create Bender's mouth.
I also finished the inside cavity of Bender with a piece of scrap sintra. That way when you open the door, you see a neat (although shallow) compartment.