I've read up quite a bit on medieval Scotland recenty. The thing I take from this is that (pre-Reformation) the Catholic church was not just a single, homogenous entity teaching the same stuff everywhere. You had religious orders moving about such as the Blackfriars, Whitefriars, Cistercians, Benedictines and so on. Add to this, each local church had its own local cults and saints. Dunfermline, for example, is strongly tied to the cult of St. Margaret. Elgin and Thomas Becket.
I have been examining pieces from churches that were damaged/destroyed in the Reformation (trying to see how they have degraded). Some timbers survived really very well, others not so much.