I saw truck at show that had button switch on the regulator box. A bolt on the hood held the button down with the hood closed. When the hood was opened the radio antenna retracted so it wouldn't interfere with the hood.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.