I will echo Rushton's sentiments and add that the Decca Mendelssohn 3rd is not only a great performance but the sonics are of demonstration quality.
The Speakers corner reissues of the Mercurys:
Rachmaninoff, Piano Concerto No.3 Dorati/LSO/Janis (Mercury SR90283) and Stravinsky, Firebird Ballet Dorati/LSO (Mercury SR90226) are the two I have purchased to date. Great sound to go with legendary performances. I am planning on obtaining the Janos Starker Mercury recording of the six Bach Cello Suites as well
The Speakers corner reissues of the Mercurys:
Rachmaninoff, Piano Concerto No.3 Dorati/LSO/Janis (Mercury SR90283) and Stravinsky, Firebird Ballet Dorati/LSO (Mercury SR90226) are the two I have purchased to date. Great sound to go with legendary performances. I am planning on obtaining the Janos Starker Mercury recording of the six Bach Cello Suites as well