Yep, replant it in straight pumice. Do it now and it won’t hurt anything. Build a small wood box (no colendars) that is just large enough to accommodate roots, and no extra room at all…and wire it in tight so it can’t move. It will not make it in the current soil/bucket arrangement.
Water sparingly, but mist the trunk and foliage as often as you can…multiple times per day. Don’t let it get too much sun.
Keep taking photos every week to monitor change.
If interior foliage yellows, it’s a good sign, if all foliage changes color gradually, it’s a bad sign. You’ll know if a few weeks if it’s survived the initial shock. Don’t expect any growth until spring.
Nice trunk, good luck.