RCA received tapes from Sam Phillips in December 1955, and where no tapes existed they used dubs from Sun singles for their masters (see below).

The released slow outtake of 'Blue Moon of Kentucky' as released by RCA on releases before 2010 comes from a copy of the 1983 pressing of Good Rockin' Tonight LP (Bopcat 100) and not from the initially turned over Sun Box #14. The master was never turned over. RCA had to use a tape transfer of the SUN 78 RPM single, until the master Sun tape was rediscovered.

A recent new transfer of the original master tape has revealed that the dialogue previously thought to come from before the outtake of 'I'll Never Let You Go' (September 1954) actually comes from before the alternate slow version of 'Blue Moon Of Kentucky'. Although this dialogue is present on the original 2012 Follow That Dream release of A Boy From Tupelo, it is not present on the 2017 Sony / Legacy re-release of the same set.

In March of 2007, Sony decided to go through all of Elvis' masters. They retransferred everything and remastered all tracks including repairing as many clicks, pops, bad edits and dropouts as they could. They have used these newly mastered recordings on their new releases since 2007 including budget soundtracks, Legacy releases, the 30 disc Complete Elvis Presley Masters collection and the Franklin Mint package. These 2007 remasters were not used on FTD's A Boy From Tupelo, the masters were all remastered again from scratch on that set.

Elvis At Sun - Restoration (Courtesy of 'Master & Session')

The C&W side of Sun 209, 'Blue Moon Of Kentucky' is one of the recordings where no master tape was turned over to RCA in the first place. A November 1955 RCA tape transfer of a Sun 78 RPM has been used up until now. 'Blue Moon Of Kentucky' is one of the worst recorded / mastered Sun masters with compression and overdone echo, but it isn't nearly as bad as the RCA tape implied. RCA compressed it further (to death actually) in November 1955. A manually cleaned up, new transfer from a selection of original Sun 78 RPM's has rectified the situation on Elvis At Sun and the improvement should be obvious.