The brass clips are
K&S Eng'nring precision tube rack pieces. These are available at lots of hardware stores and hobby shops.
I cut a piece of 3/8-16 brass all-thread rod and soldered it into place within the entire length of the upright stanchion (to provide some meat to grind into). I had to radius grind the point of junction to make a smooth square fit. Then I flame soldered the two pieces together with common plumbing solder.
The black stuff is Plasti-Dip
The Windtech clips were quick and simple; and in truth are my go-to clips. They're easier and quicker to set up, and have become my main clips.
The windtech stuff is available at any music store, and are cheap. These were the small size clips, intended for pencil mics.
I cut the clip with a pair of PVC sprinkler pipe cutters (like hot knife thru warm butter), and drilled them for the nylon shockcord hold-downs. I also used a shockcord spring clip to retain the tension. The foam is Home Despot adhesive backed insulation.
These were extremely fast and easy to make, and highly functional clips. High rec's!