Trekkie;
I believe what you are referring to as plastic tube was actually Acrylic Rod bent under heat and inserted in the engine exhausts of aircraft. Arcylic Rod can be found at plastic wholesalers and most hardware stores. Start by drawing the "arc" you want the rod to be formed into when heated, (a friend uses a paint stripping heat gun). With this drawn out on a sturdy piece of plywood - nail,screw or otherwise securely fasten supports to hold the heated rod until cooled. Now your ready. So begin heating the rod slowly and moving from top to bottom of the bend to be made. Make sure you're using heavy oven mitts or similar to protect your hands. Once you see the bend start to form or soften. Quickly but carefully place the rod in your jig and let it cool completely before removing. Once it is cool you can mount your star cruiser or whatever your choice is.
A suggestion for your "banking" type of posing. Take a wall mounting type plaque and mount the rod at the bottom of the base and "bank" your craft away from the wall.
Just a thought.
Cheers;
Gregory