I"m not so sure about those categories for deferment.
....snip....
Being an engineer didn't get you a deferment. One of my fraternity
brothers graduated with a degree in chemical engineering, one of the
hot degrees at the time (circa 1970), and got drafted a short time
after graduation.


Apparently things changed somewhere during the time between 1964 and
1970. All of my engineering peers had gotten critical skills
deferments that gave them head starts on me when I hired on for my
first engineering job at Honeywell Aero in 1966 after my service.

I didn't realize the draft rules had changed. Someone else pointed to
a web site which cited the date of the changes. I was in the latter
half of the Viet Nam years so my experiences were a little different
than yours. I was in the first group that had the birth date lottery.
I had a pretty good number as I recall - something like 181.

I had hoped that the group could compose a summary of what the draft
regulations were back then based on first hand experience like yours
and mine, but it's degenerated into more political name calling.

RWL