checked on mymopar the vin and codes correct.
it is a 383 2 bl single exhaust.
the undercoating above the axle is shiny.
Pull the rear seat, lift the carpet check the floor.
Car could have been kept in a humid garage no heat.....for the rust..
on the power brake booster,
If this car is under 50th buy it.....offer him 42th..............
Have them idle the car for 5 plus minutes and then rev engine to look at exhaust for any smoke.
Intake manifold pic at choke base looks excessive heat.
check at exhaust manifold for heat riser if it is stuck.