Hello. New with plastering in Scotland, in spain the materials and ways to do are different. I went to remove wall paper yesterday, in a 60s house, the paper took away the skim coat, kind of with plaster, no lime for sure, now I have a brown base coat, very dusty , with horse hair, not sure of the name of this plaster. Now the base plaster is not that bad, a bit uneven. How should I carry on with it in order to finish with multi? Stabilise it with pls, sbr ? Maybe a coat of bonding or similar before to make it even ? Thanks in advance !