Merely 57,500 sets were issued over six decades ago. There hasn't been a regular U.S. proof set mintage anywhere near as low since (they've been up to 70 times higher). Just one year later, the 1952 set's mintage shot up 40% to 81,980. This vintage proof set contains three coins with 90% silver content. Some sets were broken up for coveted Franklin silver half dollar proofs, which were issued only as part of complete sets. Deep-struck on mirror coin blanks. Packaging may vary.