my current job is an old stone built house that's been painted with johnstones pliolite about 8 years ago. Mostly in good sound condition with very little flaking. When I originally looked at the job the owner was convinced it had been painted in Sandtex water based masonry so my plan was to use the same again. While washing down I had my suspicions that it was oil based so asked owner again who proceeds to dig Tin out from garage and yes it's pliolite. Rang johnstones and brewers for advice...
Pliolite overcoating
Pliolite overcoating