Conn 6M Artist Alto
Date: 1956. (Drawing)
Models after 1948 didn't have rolled tone holes, but inferior drawn tone holes. Notice that as opposed to earlier Alto's, this model doesn't have a microtuner neck. Microtuner necks were dropped in 1954. In 1959 the name "Naked Lady" was dropped in favor of the name "Artist". In 1963 Conn introduced sheet-metal keyguards and a different bell-to-body brace, although the original style was still available until 1969 (source: Saxpics)
What Conn said in 1959:
Easy response and powerfull resonant tone makes this alto saxophone "the choice of artists". Exclusive bottom octave key, adjustable pivots, automatic high F and Durocast keys contribute to easy playing, fine tuning and full bodied tone. Features: balanced tone, Durocast polished nickel plate keys, bottom octave mechanism, adjustable pivots, Res-O-Pads, LUSTRE-CONN finish.