details summarized from RM's lot discription with additions from F-Register's huge database, pictures of the Slide Show by Tom Wood ©2014. Courtesy of RM Auctions
For all of us being number nerds, 16991 bears one of the fascinating numbers, just look at the body number...

16991 6/73 365 GTB/4 Daytona Argento Auteuil/Nero Daytona seats LHD US ass. # 1126 body # 1234 eng. # 16991
6/73 - completed
73 - delivered new, equipped with air conditioning, to William Harrah’s Modern Classic Motors, the U.S. West Coast distributorship in Reno, Nevada, to a Mr. Chess and was later owned by James Downing, of Cleveland, Ohio, for some 10 years.
85 - offered for sale in the New York Times, advertised as having only 5,000 miles
01 - offered for sale and sold by Dave Olimpi, showing a genuine 21,005 original miles, on Virginia plates 6-4.
02 - offered for sale by Steve Barney’s Sport Auto with 21,347 miles
06 - for sale in the Ferrari Market Letter, still sporting its handsome original colours and having recently participated flawlessly in a 1,000-mile south eastern U.S. rally.
10.5. 14 – RM Monaco Auction Lot 119 est. €400.000 - €500.000, 28,100 miles Ferrari Classiche certification