[Charlie ny]

Tony,
If the piston actuates with steady vacuum you're good, I do not believe
the piston could hold vacuum even when new let alone after 65 years of use.
I test my distributors with an electric vac pump which is capable of 25
inches of steady vac. When the vac hose is pulled off the spring pushes the piston
down pronto. I leave the piston and its bore dry so as to not attract contaminates.
Charlie ny