David Douglas Duncan

[gerspee]

https://collections.lacma.org/node/244206

And also on my attic this framed Afghan Tribesman photograph signed in pencil by David Douglas Duncan . Signing is real pencil pressed into the paper . Sizes off the print are also perfectly as original print . But what would be a proper asking price to sell it ? There's one to be found in the LACMA in Los Angeles but unsigned .

[mart]

Just google his name !  Lots of info and sales results but most of  what I found was photographic prints !!

[gerspee]

But this signed print as in the LACMA is not to be found sold anywhere  So difficult to value

[KC]

If you look at the signatures - they don't look the same. 
https://www.ebay.com/itm/333755448281

People's signatures can change over time - but there are big differences in slants, spacing, etc.  The one sold on Ebay could be someone elses' that signed for him or visa versa.

I found this page to help you in the future when you compare signatures that is very helpful
https://www.techandciviclife.org/wp-content/uploads/2020/06/Signature-Comparison-Guide.pdf

[mart]

I couldn`t even read the signature !

[gerspee]

Maybe it's time to open the frame  to see if there's any link on the backside from the print about given to maybe ? Make some time this week to do that