Hi Mitchell and welcome to the forums. I believe you are the one who emailed me in regards to my Jungle-Gyms for sale.
Are you wanting to make a Jungle-Gym that can be removed from the inside of the enclosure?
If I were you I would measure the door frame to your enclosure. Then get a piece of plywood and seal it with polyacrylic. Get some pieces of drift wood and cut them down so that they will fit inside the door frame of your enclosure. Taking the flat end of the drift wood that you just cut, drill them (using a couple of stainless steel screws) into the sealed plywood. Make sure no limbs stick out too far that it will not be able to fit into the door frame. For some horizontal pathways on the structure, pick up a few 3/4"-1" dowel rods from your local hardware store. Drill a small hole through these dowels where you intend to attach them onto the wood of your structure. These small holes are drilled so that when you screw them into the wood the dowels do not split. Now go ahead and screw them into the wood where the holes are. Seal the screw heads using aquarium silicone or GE II windows and doors silicone. Let everything dry. Now you can put it inside the enclosure, and remove it with ease. When you remove it you can easily hang it from a couple of hooks in the ceiling. Hope this helped, maybe I should make a tutorial video =P