[Bernhard]

I have never had any luck with rebuilt masters even when the cars were only ten years old.
They would work for a month to a year and then started to leak and bleed off pressure.
Since then I have always used new and never had an issue.
I would only trust a quality sleeved master cylinder bore I'm done with honed bore masters.
If one could locate a core from a dry climate area then maybe it might work.