Mentioned by guitar tech Phil Taylor in this September 1994 Guitar World interview (one of a trio from the same issue).

GW: How many guitars does he use during the course of a performance?

PT: About seven. In addition to his Strats, he uses a Telecaster tuned to a drop-D for "Run Like Hell," two mid-Eighties Gibson J-200 acoustics -- one tuned to standard pitch and the other tuned to D,A,D,G,A,D for "Poles Apart" -- a Chet Atkins electric-acoustic and two lap steels.

In 2019, Gilmour's 6120 was auctioned off for $100,000 as part of Christie's The David Gilmour Guitar Collection auction with the following item description:

THE FRED GRETSCH MANUFACTURING COMPANY, BROOKLYN, 1960/61 A HOLLOW-BODY ELECTRIC GUITAR, CHET ATKINS 6120 Inlaid at the headstock Gretsch and labeled internally THE FRED. / GRETSCH / MFG.Co. / 60 Broadway / Brooklyn (11), N.Y. / Model no. 6120, Serial No. 39884 / MUSICAL INSTRUMENT MAKERS SINCE 1883, Gretsch and applied at the pickguard, along with Chet Atkins, with original hardshell case bearing a label inscribed GRETSCH 6120 #39884 and SERIAL NO. DG1066; accompanied by a facsimile copy of the sales invoice from California Guitar to Mr. Dave Gilmour, dated 15th December 1979 Length of back 20 5/8 in. (52.5 cm.)

David Gilmour purchased this 6120 from Frank Lucido’s California Guitar, Ventura, California, in December 1979, during a brief interlude between completing final recording and mixing sessions for the 1979 Pink Floyd album The Wall at Producer's Workshop in Los Angeles in November 1979 and beginning rehearsals for the upcoming The Wall Tour in January 1980. Gilmour kept this guitar for studio use.

In this picture Johnny Marr can be seen playing this guitar.

"The Gretsch 6120 that I used to write and record "Stretch Out And Wait". You can hear it on "Is It Really So Strange?" too. I got it from The Who and It's one of the best old 1960's Gretsch's that I've played. I got introduced to a guy called Alan Rogan who used to work for Townshend, Clapton and Keith Richards. I ended up getting a load of guitars off him. That's where the Gretsch 6120 came in. It's the one Townshend played on loads of Who stuff. I don't know why he sold it to a geek like me."

Johnny used this 6120 on 5 out of 6 documented dates of the Smith's final 1986 tour, for Meat Is Murder only. It was tuned to Open G, the same tuning used on "Stretch Out And Wait" and "The Headmaster Ritual".

Source: http://www.smithsonguitar.com/2008/12/johnny-marrs-gear.html

Little is known about where this guitar came from; it was used on the "Paperback Writer" session and then apparently stuck away at Lennon's home. Two years later Lennon gave this guitar to his cousin David Birch, who in '63 had also received a Hamburg-vintage Fender Vibroluxe amp from his cousin. "Upstairs in John's house in Weybridge, he had his den and music room. It was full of tape decks, keyboards, guitars, etc. The two guitars I remember were the blue Fender Stratocaster and the Gretsch 6120. It may have been cheeky, but I asked him did he have any spare guitars, as I was trying to get a group together while staying with Mimi in Bournemouth. I really fancied the Fender, but that was a no-no, but he said I could have the Gretsch. I was over the moon, as you would expect." Birch loaned this guitar to The Beatles Story in Liverpool for display in 2010, and he remains the enviable owner of a genuine Beatle guitar, not to mention amp (below)! As of June 2012, this guitar is on loan to the Rock and Roll Hall of Fame.

Used a lot during the early days of Buffalo Springfield.

Music Radar talks about this guitar in this article saying "Townshend used the hollow-body on many of his post-Tommy Who recordings - Who’s Next and Quadrophenia are two stunning examples - and, after the instrument was repaired (only the neck was broken), he continued to employ it on both band and solo albums."

He had this one until he gave it to Pete Townshend, who made significant progress on "Who's Next" with this guitar.

Excerpt from Guitar World interview: "It was also Walsh who laid on Pete Townshend the 1959 Gretsch 6120 and 1959 Fender Bandmaster amp that Pete used to create the unforgettable guitar sound on Who’s Next."

In this TV appearance, Chuck plays a Gretsch 6120.

Byrne plays Gretsch in Live Union Chapel

Buck can be seen playing the guitar live with Joseph Arthur, as confirmed on Premier Guitar’s website. He has also used the guitar with R.E.M.

R.E.M.’s Peter Buck, shown here playing a Gretsch 6120

Brian Setzer’s guitar tech, Tyler Sweet discusses the 1959 Gretsch 6120 at 0:25 in this Rig Rundown from Premier Guitar saying, “This is Brian’s original guitar that he played in the Stray Cats. It was basically in all the videos and he’s had it for a long time. He bought it when he was just a young kid and he’s broken it back out again in the last year. It’s sounding great and he’s totally digging it.“

Stuart Pot (2D) uses a double cutaway Gretsch 6120, identifiable by its three switches, in black with gold hardware, as demonstrated in a promotional image from 2018's The Now Now.

Lake states in this interview that he uses a 1959 Gretsch 6120.