Watching thread with interest, as admire how you have got stuck in and learning as you go. I am trying to get a clear plan and design before spending a penny......so happy to learn from your journey.

No help on electricals, but back to printer paper plans. I use this all the time for woodworking templates. You want a spray can of 3M '77' good for temporary and permanent bonding light weight materials.

Keep going and keep sharing gotchas!