Contemporary vacuum cleaner dust brush heads have bristles in some combination of [long | short] with [flexy | stiff]. The long + flexy combination results in the bristles jamming the inlet and the short + stiff combo seems unsuited for complex surfaces. Shaking the Amazonian dice brought a different combination:
That’s the new one on the bottom and, contrary to what you might think from the picture, it is not identical to the one just above it.
In particular, the black plastic housing came from a different mold (the seam lines are now top-and-bottom) and required a new adapter for the Kenmore Progressive vacuum cleaner’s complicated wand / hose inlet, with a 3/4 inch PVC pipe reinforcement inside.
Early reports indicate it works fine, so I’ll declare a temporary victory in the war on entropy.
I’m still using the same OpenSCAD source code with minute tweaks to suit the as-measured tapers.