You are looking at (10) original as issued US Proof sets from Philadelphia Mint. NONE of these 10 sets have been opened (see photos). Note that the 1956 set has about 1-1/2 inch tear on one edge of envelop but no way to look inside and set remains unopened.
These make great Christmas gifts for kids and adults. The item "(10) UNOPENED US Proof Sets-Complete Run 1955 Thru 1964" is in sale since Saturday, November 16, 2019. This item is in the category "Coins & Paper Money\Coins\ US\Proof Sets".The seller is "tivolirose" and is located in Lincoln City, Oregon. This item can be shipped to United States.