I made a small J hook that I stuck between the spring and the arm, turn it 90 degrees and it keeps the support from folding. Not a fix but it works until we can get some new springs.
Like 69a said, I made a plate that mounts to the car and the license plate mounts to the plate. I've done it a few times, saves drilling holes in the plate.
Electric would sure beat those vacuum tubes and the vacuum valve and even eliminate the worry about keeping the vacuum can lubed. Looking forward to a solution by you guys.