General Dynamics Undersea Station concept photo circa 1968 found on eBay.
URL:
http://www.ebay.com/itm/1968-Undersea-Station-Concept-US-Naval-Civil-Engineering-Lab-Press-Photo-/160851732264?pt=Art_Photo_Images&hash=item257382a728
URL:
http://www.ebay.com/itm/1968-Undersea-Station-Concept-US-Naval-Civil-Engineering-Lab-Press-Photo-/160851732264?pt=Art_Photo_Images&hash=item257382a728