Any Rock & Roll fans here? Need help IDing photo of 2 sleeping musicians (I think!)

Someone at my estate sale today saw this photograph under some magazines & took a photo of it, then a little while ago he text me asking if I'd hold it and he'd come buy it tomorrow. When I asked if he found out who it was, he said "No, I just like it"
Just to be sure I'm hoping someone here can tell who they are - I thought Allman Brothers/Greg Allman & the buyer said he thought they were from the Grateful Dead - I'd like to know who they are so I can get an idea what the photo is worth.
Thank you!

 

The Allman Brothers.

Debora

 

Ditto.

 

Annie Liebovitz. 1971. Details here.

https://www.facebook.com/GreggAllma...by-annie-leibovitz-from-ol/10156256829325698/

Debora

 

You've been sniped!

Debora

 

I'm almost postive it's a photograph - is it worth opening to see? Were there more than 1 & if so were any put up for sale to get an idea what it's worth - he offered $20(!)?
I may open back of it just to see if there is any info about Annie Leibovitz rights to photo, etc, right?
Thank you!

 

Duane on the left, Gregg on the right.

Duane Allman: my favorite rock and roll guitarist of all time!

 

It's a photograph, but it is sandwiched between foam board back and a frame/matting on front of it that are glued together.
I looked and found 2 photographs of Yoko and John that sold for $26,000 + other photographs by her for sale but none of this photograph - is it a common photograph available (a real photograph not a print, etc)? Can anyone find one for sale or has sold to get an idea if it has any value - or is it not a big deal & the $20 offer fair?
Thanks

 

Here's one of her photographs mounted & matted; which is what mine looks like
https://www.ebay.com/itm/333919891505?hash=item4dbf2d3031:g:FCQAAOSw1K5feK~y

I also found some of her photographs of celebrities by Anneie (Demi Moore, etc) selling for around $295 - but again none of the Allman brothers for sale (there are a lot on pininterest but if they are for sale I can't tell (pininterest - to me - is like a photo album of everyone's photo albums!) - If this is worth $200+ I'll sell it myself on eBay!

 

Agree.