I can't make out those signed letters when I zoom in. That is not a guitar I've seen before as best as I can remember. It's Fenders version of Gibson's hollowbody ES-335. Duane had one of those and I think it was a blond burst and maybe Dickey gave it to Eddie Shaver and now Willie Nelson has it in his safe. At an Ohio show in 1970 Duane played that Gibson and Dickey played an old Strat. The next ABB show I saw with no Les Paul on stage was in 1997 with Jack on a G and L Strat type guitar and Dickey on a Fender Strat.

Duane had several Strats he used in Allman Joys, Hourglass and session work. Also a Tele body with a Strat neck. When the ABB formed he moved to the Les Paul and was continually looking for something better as he switched Les Pauls several times looking for one that he liked better than the other and the last Les Paul was a tobacco burst and Dickey gave him a SG that Duane used for slide but some say he didn't use it much but I remember him playing slide with it several times.

I wouldn't pay much for this guitar. But one of the Les Pauls Duane used in the ABB or that Strat he used at Muscles Shoals and in Hourglass ( Hey Jude by Wilson Picket) would be valuable. Supposedly Graham Nash has the SG Dickey gave Duane.

There is a 1966 Fender Coronado II listed here: https://www.groundguitar.com/duane-allman-guitars-and-gear/

Duane allegedly owned a 1966 Fender Coronado II in his early career. The guitar was apparently for sale on eBay recently with letters tracking it back through various owners to a Macon Music Store where Duane supposedly traded it in for a Les Paul Jr in the late ’60s.

However, even if Duane did own this guitar at one time, there is no evidence that he ever actually used it.