The brake booster was not the prime suspect of the malfunctioning brake system, as mentioned I initially did not plan to refurbish the booster, only the master sylinder. When one of the bolts securing the master cylinder to the brake booster snapped however, another route was chosen.
If the booster was not operating perfectly before, I would guess the culprit would be the internal sliding surface seal. I'll have a closer look at the old parts before these are discarded (or stored).
The parts kit come from Harmon Classic Brakes, "Booster Major Repair Kit". Item no.: 62-653
