Z-axis Linear Rod and Leadscrew Stabilizer for Geeetech i3 Pro B printer with 8mm acrylic frame

In 2015 I purchased a Geeetech i3 Pro B printer kit with 8mm Acrylic frame. Attempts to use this printer as it was originally designed always resulted in very rough vertical walls due to poor mechanical tolerance with the Z-axis threaded rods. This caused significant problems printing any part which required tight tolerances, such as parts with integrated print-in-place hinges. I tried several 'solutions' which I found here on Thingiverse and on other internet sources, including the common pa