Thanks for that correction. My Decca discography does not list a CD at all and Michael Gray's Beecham society discography of 1997 only lists excerpts on 2 separate CDs in the same series [09026 61712 2 and 09026 61488 2] as your complete set. Another CD, apparently of excerpts, was also issued as RCA 9865 2R, possibly US only.
MDT currently lists the 1956 RCA Messiah as still available with the same catalogue number as yours; it also lists his more or less complete 1927 version on Pearl GEMM CDS 9456 should anyone be interested!! The excerpts discs are not listed.