No states retroactively enforce modern safety standards against antique cars.
You can purchase lap belts for your truck. There is a thread on this forum that shows a good installation method.
Rebuilding your brake system should be pretty easy. All the parts are available new. Everything else to get it operating is also pretty easy to source.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
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