Here is the plastic tank, sans metal sleeve. Screwdriver marks on one side, shallow dremmel cuts on the other side. So much for a surgeon's touch. The tank is intact, all it needs to be presentable is a little epoxy to fill the gaps, wet-dry sandpaper, and a buffing wheel.
The metal sleeve rests against the lip molded in the tank.
No molded lip at the bottom. It looks like the threaded ring is inserted after the metal sleeve is in place. Unsure if it is glued in place of if friction holds it in place.
Perhaps the threaded ring could be removed using a hot air gun. I will have to wait for my next Evod to arrive to find out.
"A is A" - Aristotle