You hit the jackpot
coolgrly 
these are wonderful, I am not surprised they attracted a swarm of keen vintage hunters.
1. The first is from the very late 1970s or very early 1980s
2. Thus highly desirable bag is from the mid-1970s and is one of the last version of the design at this issue. Look after it well, it will be very hard to acquire another just like it
3 Early GAC very late 1970s-very early 1980s
4. I'm pretty sure this is a 1960s bag (not before 1966) I will double check this one. Remind me if I forget to come back to you