A bit late in the day but have you tried Havard Gimse / Royal Scottish National Orchestra / Bjarte Engeset playing the Grieg on Naxos ?.....I find it is a very listenable account.
I have just realised I had the Perahia /Davis set on cassette but as I have not listened to a cassette for about 10 years I had forgotten it . Played it this morning on the cassette player on the kitchen mini hifi . Two absolutely textbook performances . The Grieg utterly full of poetry in a way that wholly escaped the young pianist in YMOTY to my ears and the Schumann is a particular joy from start to finish every note just sounds right.