The only correction I can suggest is the end dates for manufacture of the cushion cased version. I believe these were made concurrently with the 729X models for some time into the latter's production, perhaps even until the 7002 was introduced. I have a 6309-7049 (which I'm wearing right now) that by all indications was manufactured in October 1987. Several other individuals, including Aaron (Cobrajet25), Shawn and Randy M. have indicated that they either have or have seen cushion case models produced into the latter half of the 80s.
Here's a pic of it that was cropped from another picture.
And here's a post where I brought up this theory. There are a couple of other links inside which may help with your dissertation.
http://www.network54.com/Forum/78440/message/1137456617/
