Launched in 1929, Decca is famed for turning down The Beatles, but it did have an impressive list of successful acts - Billy Fury, The Tornados, Rolling Stones, Moody Blues and Tom Jones to name but a few. The unboxed red label was used at least until 1965. In 1966 Decca changed its singles label to one with a boxed logo, but what happened to the LP label is unclear. Even Decca themselves cannot tell me! In the absence of any definitive answer, I shall therefore base the following information on the experiences of both myself and other dealers I have spoken to.
For issues from 1966 to 1969, a few releases were made with the unboxed logo, but the vast majority of LPs appeared with the boxed logo label shown opposite. One other significant difference was that this label was smaller than usual. It would only be in the mid seventies that Decca records would revert to normal size labels.
This information is based upon the fact that some issues, like The Rolling Stones' Big Hits (High Tides and Green Grass) released in 1966, would have achieved the bulk of their sales during the following two years and yet unlike Beatles releases for the same period where originals are quite commonly found, hardly any unboxed logo pressings of Big Hits `can be found. It can only be that all or most original pressings had the boxed logo.