The plan was to have the boxes screwed together with a neon Perspex divider that I could light up. This is just my desk lamp shining through from the top but gives an idea of what I want to achieve. I made a mounting block from a piece of ½” Lexan. I got a number of small pieces of this for free from the off-cuts bin at the plastics supplier I go to (I did ask them first). I cut it out with a hacksaw and filed the edges and corners before sanding and polishing. The holes are 6mm drilled using a drill-press and Plexi-Point drill bit. Nice silky edges and I cut the block so it would fit just inside the corner curve of the boxes and not overhang (an overhang just didn’t look right when I was messing about test-fitting and thinking up ideas for the mounting). The back of one box showing location of screw holes, LED holes (for the centre divider lighting) and holes in the top to pass wiring through. Drilling the bottom of the boxes for the stainless steel hose (you can see the small pilot holes I have drilled to allow accurate lining-up of the step drill). You can also see in this picture how I have already used screws to join the whole assembly together. This gave the box more stability during the drilling process and allowed me to drill pilot holes through both the boxes and the divider that lined up perfectly. The box was then taken apart and these remaining pilot holes were enlarged on each piece individually due to a requirement for different sized holes. Drilled the mounting holes in the top of the case (6mm). The finished pieces of the junction box. The three small holes in the divider are where the wiring will pass between both the boxes.