NAC was a firebase just to the West and a little to the North of Da Nang in Quang Nam province.  The NVA called that province Quang Da.  The XXIV Corps artillery supported the 1st Marines from FSB Rawhide, Combat Base Ross, and

the 2/94th at FSB NAC (Northern Area Cantonment).  Rawhide was just below the NAC and Ross was below that just at the border of the next province down which was Quang Tin called Quang Nam by the NVA. 

Mr Jones by the way is a British civilian.  I think he said he lived in Birmingham, England.  He said he picked up the photos in a pawn shop or something.  He is a collector of military patches.