I am far enough down this path that I figured I'd share on the forums.
I got the itch to make my own Holocron about a month ago and have been working on it since.
I've shared on Facebook and a few other places so if you've seen it already sorry...
I initially started doing the scratch build totally by hand, then realized I could use my vinyl cutter to cut the styrene more precisely. So I made my illustrations in Illustrator and sent them over to the cutter. Then it was just a matter of welding the pieces and sanding them down.
Next step is claying up the pieces and prepping them for mold making.
Then the pieces are cold cast. I've been experimenting with different powders. Here you can see copper and graphite finishes.
Eventually this will get some cool electronic features, but I still have some work and refinement to do.