After figuring out the different steps in how to assemble such a billboard I again made a CAD drawing and got it laser-cut from my friend.
I designed the billboard in 3 layers on 1mm MDF (Medium Density Fibreboard)
With the tip of my hobby knife I pricked the holes of the "speaker" out.
Then I glued the "knobs" on the engraved spots.
Finally I glued and clamped the 3 layers together.
I painted the billboard with a brown color and glued a billboard ad from the 1940's era into the frame.
You'll find tons of advertisements on the internet. Most are jpeg's and with a little scaling on the computer they can be printed out on a normal printer.
After I had assembled the Art Deco Billboard I thought about what I could do with the leftovers. The panels that had been discarded from the frames give a neat rectangular billboard.
For the new frame I salvaged the small strips from the carrier sheet, which are a scale 6" wide
With my NWSL chopper I cut the strips at a 45° angle.
Then I glued the frame around the edge and voilà, a spare billboard from scrap pieces.
I painted the billboards dark green and applied period appropriate ads.
Now I need to build some legs or probably attach them to the side of a building.
This Art Deco Billboard will be available soon. Watch for details.