I noticed the dual master cylinder in the under hood photo. I am impressed.
I previously worked for a car dealer that was having a '64 car restored for his personal usage. For many reasons I attempted to talk him out of that particular car due to the poor condition it was in.
One of our many disagreements during the reconstruction (yes, major rebuilding)
was to convert the brakes to a split system. He could not understand why it was necessary. The dealership technician and I both asked him if he had ever driven a car and stepped on the brake pedal and had it go to the floor.
He said he had not. Both our replies were "Well, you don't want that experience".
Last time I was in a vehicle that this occurred was in a 71 Ford cabover fire truck. We were approaching a red traffic signal when the driver yelled "No brakes".
I grabbed the air horn cord and pulled. And pulled hard. Surprised I didn't break the cord. We got stopped after clearing the intersection. We did not lose air pressure, the treadle valve froze up due to moisture in the system. Tow truck for the fire truck, chief's car back to the station for the crew.