Why were these made? How many were made? How do I spot one in circulation? Does it have a prooflike satin finish? Back in that day, it was apparently common for the Smithsonian Institution to receive some of the first coins minted that year; let's face it, they receive everything we'd like to have, and I won't even start because it'd take hours on end. But, why would the Mint make just 20-50 estimated special mint sets? Possible reasons include preparation for 1965-67 mint sets, potential intended limited mintage coins to ring collectors' chimes, or maybe even 1964 planned special mint sets where some got out before the idea was shoved off the table. What is your theory on the suspiciously low mintage of these 1964 SMS coins?