It is impressive a 1968 design would still be in production in 1994. Much like CTA's 5000s share the same car shell as the 2600/3200 and basic design from 1976 (2400 series). That and the 1970 NJDOT Comet design (lasting to 2001).BuddR32 wrote:The M1-M6 design was considered antiquated by the time the M7 came around. Also, changes in crash-worthiness, egress windows and the like the design would be totally different anyway.
The closest analogy in the automotive world be the Jeep "SJ" (full size) Wagoneer, introduced as a 1963 model and lasting 29 years to 1991.