Gary,

I just looked this up in the VW manual. Naturally they have pictures
of the NORMAL carbs 30pict, 34pict but nothing like you mentioned.
HOWEVER, they do talk about the EGR value(Exhaust Gas Recirculation)
and testing proceedures. That devices is hooked to the carb to pull in
and REBURN emissions. Also, an autostick tranny requires two vacuum
connects, one manifold to supply the muscle to power the clutch, and
the other (carb connection) to help assist disengaging the clutch. I
have an autostick, but lack a seperate port so it's tee'd into the
advance line...
OK, so all this said the two ports on the side of your carb will
control the distributor advance, and EGR emmission along with any
control for the autostick. Those ports if not used should be plugged.
You can plug them, start your engine and manually open the throttle a
bit and then remove the cap and feel the suction, the advance will kick
in once you open the throttle so you should be able to pick out which
one of two is TRUELY advance. The other one could have suction all the
time, I'm not sure on how the EGR circuit is plumbed. Hope this helps,
the book really doesn't go into detail on your specific question.

Scott