Does the navy sell used or surplus tailhooks? How do these end up in civilian hands?
Many times items such as this are presented to a pilot when he retires or leaves a unit. The items are not new or serviceable, they usually have structural failures or have reached the end of their service-life. Many aircraft parts are replaced before failure. . . and rightly so, IMHO.
Some excess or end-of-life parts are sold to certified scrap bidders, museums and other such people or organizations. Some parts may be purchased by individuals. If interested, I suggest contacting AMARC (http://amarcexperience.com/Default.asp), as they are the “COSTCO” of used military aviation parts. AMARC in Tucson is known as “The Boneyard” to military pilots..