If you are ok discharging the tv, decase it. Making your own mounts for the tube will make it sturdier and perhaps lighter than bracing a cased tv. Also, decasing aids in cooling allowing more air flow over the tv components. All I would do is get some 1x4s (or whatever would pad the sides out near the tube once centered) and screw and glue them to the sides of the cab giving you some space to screw down the tube sides. I'll post a pic when I get home of what I did with my cab to give you a visual idea. Then mount the TVs board using pcb stand offs or cut a plastic bic pen and use wood screws to make your own stand offs. Getting the tube in is the hard part, get 2 good beer loving friends to lift and hold it in place while you screw it down in exchange for a couple brews.