Yes, that is correct. 105 became New 105 (1987-1989). 600EX become New 600EX (1984-1987) and Dura-Ace EX became New Dura-Ace (1985-1996). In the case of New 600EX and New Dura-Ace, Shimano quietly dropped the 'New' designation from their literature after 2-3 years, once the new group was established with the public.