According to Rob Cook's "The Ludwig Book," copyright 2003, the first catalogued 6.5" Acrolite Model 405 was in 1994. However, Rob states that "apparently there were a few made earlier." I recommend that book to you.

Regards, mb

It was much earlier than that. Ludwig made some for the New York City Board of Education starting in the mid 60s and into the 70s They weren't sold to the general public so they are pretty rare.

https://www.drumforum.org/threads/1971-ludwig-6-1-2-x-14-acrolite-snare-drum.122480/

https://reverb.com/p/ludwig-6-dot-5x14-nyc-board-of-education-acrolite-snare-drum-with-keystone-badge-1966