I received from Naxos a recording of Paul Badura-Skoda playing two war horses - Tchakovsky's First and also the first of Franz Liszt coupled with Rimsky Korsakov and his attempt at a piano concerto. These were recordings from Gramola and were all done in the 50s. Please explain how this makes sense other than a way to fill the CD/Download? The Rimsky piece is definitely unsung - in fact I last heard it on a Vox lp.
Again (quite a litany !):Hypérion did it (with the Balakirev two) and Chandos too, a work illustrating his fame as master of orchestral colours.