Unidentified - Lecanora polytropa?

I thought this one would be easy but no candidates so far. The ascus was KI+ but couldn't identify the reaction so may come back to this one at a later date. When dried out the colour looks different so I suspect that lack of any visual matches has put me off making a confident ID.
Hymenium: 100
Epithecium: 7.5
Spores: 10x7.5