Yes, AMC was all over the place with their vacuum layouts depending on year and location (ie: California had it's own special layouts for a while).
The combo ported/manifold layouts seem to appear in the early 80's along with the AIR pump system. When they switched to the computer-controlled Pulse Air system, the vacuum layouts begin to show only manifold vac to the dizzy, like the layout I posted.
I've read that ported vac advance was just a bandaid fix to get around new emissions requirements. The engineers figured out that by retarding the timing at idle, combustion temps increased, allowing the AIR pump system to have a greater affect on emissions, at the expense of performance.
I got tired of all the arguments so I just called Davis and asked them. They said, MANIFOLD! I've tried it both ways. I have a Weber 38 and No emission crap. The only vacuum lines I have are advance and brake booster, and to be honest it seems to run just fine BOTH ways!
Beer is the answer - it doesn't matter what the question is!