FLOWN Liberty Bell 7 bolt. An approx. 1-inch bolt encased in an approx. 5 x 5 in. lucite block with descriptive text. The bolt was one of the few parts unable to be reinstalled after an extensive restoration project. The Mercury spacecraft was recovered from the Atlantic Ocean floor at a depth of over 16,000 feet during July 1999. The Liberty Bell 7 was lost for 38 years since sinking on July 21, 1961.