Very neat coins and your photos are very well done too ! When my wife and I visited the Numismatic Gallery and saw the coin exhibits the first thing I wanted to see was the mint state 1793 Chain Cent. It is a great coin, but in my opinion needs brushing, so I don't think they do any cleaning or anything like that to the coins after they are displayed. The Eli Lilly gold collection is fabulous to say the least. It was all good! I want to go back sometime soon.
The 1933 Double Eagle is a more recent display, and I want to ask you what you thought the three clips are made of that hold the coin in place. They look like metal of some sort? I can see the 1913 Nickle is being held by large clear plastic clips, and I wonder why they didn't use an inert material on the gold coin. The Smithsonian is an amazing place ! Thank you for sharing,
Phil