The US Mint normally made arrangements for persons connected with a new coin, or who had a compelling interest in new coins, to purchase examples. This could be done during initial annual production (as with the Director or Sec Treasury), or at a formal ceremonial striking as with the Kennedy halves. There was, and is, nothing illegal or under-the-table about this - it is a common courtesy. A similar situation was offered Denver Mint employees at first release of 1964-D halves - each could buy 2 new halves on the first release date. Philadelphia Mint did the same, and a bag was delivered to Treasury for a similar purpose. Smithsonian got coins from new dies in a similar manner whether direct from each mint for via the Director's office.
The who point is that these were not special coins made for special people, or from some secret purpose or test. The hyped "SMS" coins are nothing but normal pieces, from normal dies, made on normal equipment, for normal purposes. The ignorance that led to calling these (or some other coins) "special" lies in the failure of some to research, learn and understand how and why coins appear as they do. (Some will recall that only a few years ago it was believed that new dies were polished and that accounted for PL Morgans and other denominations. I did the research and digging in records to understand what was really done. Now we understand, correctly, that PL coins come from dies polished during repair and touch-up as part of normal production.)
One cannot slap "special" or "specimen" or some other title in a coin arbitrarily - it MUST be proven. That demands understanding the processes, equipment, methodology and operational standards of U.S. Mint production and management, along with the range of appearance generated by normal die use. (Many readily accept Early, Middle, and Late die states, yet fail to apply the concept to Initial and Terminal die states.)
Frankly, I feel I'm talking past the dollar signs; the truth is just too inconvenient and costly for the hobby business to admit.