It's not spring yet Mike and my Steelers are not in the playoffs. No reason to get out of my cave.
I do have my aluminum arch hinged. It was completed by the origional owner. He had it cut and hinged in Florida. You remove the forward bolt on each side of the arch and fold it towards the aft. It was not cheap to do.
You need to remove the whole arch after removing your electronics and wires.
Cut the arch in two.
Add vertical panel/channels for structural integrity.
Add the top and bottom sill plates.
Add access holes in the top and bottom plates. Create a lip in the bottom plate access hole and then have the top plate sits on top of bottom place so water does not enter. These will be used for your cable/wires.
Rewire your electronics and extend the wires with slack when you want to fold the radar arch.
Also you will need a support after folding the arch down.
The arch needs to be welded, ground, sanded and painted. You need to have someone who can TIG aluminum then find someone who can paint aluminum and have it stay on. Painting aluminum is a multi-step painting process and is difficult to do. It also needs to be baked after praying. You can do a web search on painting aluminum and it's process.
Let me know if you need additional information.
Here are some pictures.