Added a hollow interior and a plug to seal after filling. Ideally something like sand, but pretty much anything that can fit through the 10mm hole can be used as weight.
Outside looks identical. About halfway up, the hollow interior sides slant inward in a 45 degree cone towards the fill hole so it can be printed with no support. Print with support only touching the build plate to handle the curves on the bottom. In PLA with my go-to gyroid for the thick walls. Allowed me to use old stuff that I probably wouldn't have trusted to a delicate print. I expect that the plug REALLY needs to be TPU.
Needs enough sand or alternative weight to outweigh the soldering iron and the armature, but not by a lot more. Haven't calculated the ideal amount that it should exceed the other side by.. Probably will vary some with the soldering iron selection