Hi, Please confirm, does it have vac' retard and mechanical advance, or vac advance?

Vac retard was only used as a pollution control gimmick on early 70's cars - it retarded the timing at idle to reduce NOX emissions at idle. That's where the feds tested emissions back then. so if the ignition advanced as soon as the pedal was pressed and it started emitting NOX again, it didn't matter.

The older distributors have both vacuum (load) and mechanical (RPM) advance. The ignition timing needs to advance as the engine revs higher, and also, lean mixtures bur more slowly, so if the engine is under more load you can advance the timing a little more than under a light load, at the same RPM.

The vacuum retard lines are attached to the manifold past the throttle, so they see the most vacuum when the engine is idling. The vac advance lines are attached to a port on the carb that senses vacuum in the venturi - so the more air passing through the carb (more load on the engine) - the more vacuum it sees.
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'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)

Make sure at idle the vacuum canister does not have vacuum. No vacuum until the throttle begins to open. My advance springs were weak and allow the vacuum to pull the advancement too fast and didn't return the advancement back to the stock idle setting. Advancement was also to far advanced. Made for dive-ability problems.