According to this month's Gramophone, this performance was recorded by Lyrita for release in August this year
It beggars belief that the BBC and Lyrita regard this broadcast performance as "un-releasable"... on what grounds?
:o
I think that the situation may well be that the soloist who experienced difficulties during the performance may have refused permission for the recording to be released. If you recall Brian Rayner Cook refused permission for the Marco Polo recording of Havergal Brian's Symphony No.5 "Wine of Summer" to be released because of his dissatisfaction with his own performance.