Brake Booster Not Functioning? 1963 Dodge 440

My buddy has a 1963 Dodge 440. 383, 4-bbl, AT (push button), A/C and Power Brakes (drums front and rear).

On the first trip out this year he said he needs to push the pedal extremely hard to stop. He said it's worse than the manual brakes he had on his 1965 A100 pickup.

Did the power brake vacuum assist die? How do you check if the vacuum assist is functioning? What else could/would cause the hard pedal? Cracked/split hose? Where to begin?

I would spend some time checking the booster hose and fittings. Some booster fitting have a 3 way vacuum connector and if any oil gets inside these rubber hoses it gets soft and larger and if the smaller hose comes off, it sometimes hard to tell by the running of the car. Mine was minor transmission leaking into the vacuum system, was not smoking(yet). Or was with PCV system, was a while back.