Thanks! Yes, I did. I bought 3 meters of 1" square steel tubing with the appropriate corner pieces, cut them to the right length, then assembled.
I built the base out of plexiglas because I had a big scrap piece laying around, and I didn't have enough wood.
After cutting all the pieces, I painted it all with semiflat black spray paint.
I didn't have any motherboard risers, so I made some with screws & some aluminum tubing stock I had leftover from another project.
To get the screws in the plexiglass I drilled a pilot hole for the screw, then before screwing it in; heated it up with a torch. The hot screw melts the plex a little when going in and creates threads.