Period cottage - identify what paint was used on walls

[Alel]

We bought a cottage six months ago and have not done any decorating. We have tried to let house breath, dry out and warm up. One corner of living room is damp and paint peels. Moisture reading shows the corner is damp to about 6 inches high. We are not sure how to determine what paint type has been used on walls e.g not breathable or could be masonry paint. Minor cracks/some lime plaster areas sound hollow but otherwise walls reasonably sound. Does anyone know how we determine the paint type on the walls and how to remove old non breathable paint and let wall dry out.

Bare walls show signs of being powdery/ flaky.

I suspect upstairs they have used normal paint but all walls appear ok.

 

[DaveG]

If the paint is peeling this suggests it’s not a breathable paint that was applied. If areas peel away you may be able to get a paint scraper to pull away more but you’ve got to be careful not to gouge the plaster.
The plaster under this paint is definitely lime and not pink plaster is it?

 

[Alel]

The plaster is lime and not pink plaster - thanks