Actually, the recording engineer wasn't Bill Porter or Selby Coffeen. Bill Porter didn't begin working at RCA Studio B in Nashville until March, 1959 and he didn't begin working with Elvis until March, 1960. Selby Coffeen was the engineer over at Owen Bradley's Quonset Hut on Music Row in Nashville. The correct recording engineer for the June 10-11, 1958 Elvis Presley recording sessions at RCA Studio B is Robert Ferris, the same guy who engineered Elvis' January, 1956 and April, 1956 sessions at the old RCA Studio on MacGavock Street.
I believe Tunzi in some of his early recording session books attributed Selby Coffeen and I believe Ernst Jorgensen in his "A Life In Music" simply listed the letters RLJ. The RLJ I believe are the initials of the engineer and I believe he took these initials from the tape box from the sessions. However, he misread the initials as RLJ when in fact they say RLF. This tape box can be seen in the FTD book, "Flashback."
There are a series of books put out by Mel Bay regarding Chet Atkins. In one of the books, Bill Porter writes about how he started at RCA Studio B. What he writes is pretty interesting. He basically said that Robert, or Bob Ferris and Chet Atkins got into a heated argument that from recollection, led to a physical altercation of some sort, on Atkins part. I know, he's known as the "country gentleman," which makes it that much more surprising. He says that Ferris was transferred elsewhere and that he was hired to replace him, with Ferris basically training him for roughly a week before he left for good. Porter also talks a lot about how Atkins taught him to mix and master sound. There are some great quotes that he talks about this.
Here's one of the books:https://www.amazon.com/Mel-Chet-Atkins- ... het+Atkins
Here's the other:https://www.amazon.com/Mel-Chet-Atkins- ... het+Atkins