After the acrylic barrel parts had been worked, I received the first of 2 sets of 3D printed parts - here, the crystal "bar" and the rear grip plug which will fit into an accompanying socket in the 3D printed rear base (more on this below).
My plan was to make a 2 part mold for the crystal bar, but unfortunately I didn't seem to have put down enough mold release and instead I created a giant silicone brick. It's not a total wash, I was able to cut along the sides to make a usable mold. It's sloppy and it meant there was a lot of cleanup work needed for the final parts, but it worked.
Here are the pulled casts of the six crystal bars, cast in Smooth-Cast 325 which cures a slightly amber colored clear. Since I will be lighting the bars and sanding them to get a "frosted" look, the slight color is not a big issue. I also pulled casts for the 1 part mold for the crystal "cages", but I didn't take any progress photos of that. Sorry.
Lastly, here is a mock-up of everything. Most things are held on with tape here, I had purchased some screws to hold together the front parts but I had to buy more because I didn't account for a few things.