[GREENBIRD56]

I'm going to assume at this point the car has been running before. It has the necessary road grime to imply it has been run - not freshly assembled and parked.
The mechanical tachometer cable appears twice in the available pictures - but seems to just droop over the kickdown linkage behind the D.S. cylinder head (or not?). There are a pair of extraneous wire terminals attached to the coil - which would allow for an electric tachometer to function. It hasn't been mentioned if the tach was in the dash position or otherwise. That would solve that one.

I'm not certain if you can put the double can advance set-up on an earlier distributor. The engine in my '56 was a 312 four barrel - with auto trans and one of these distributors. One of the chambers of the advance simply "offset" the other - added an amount of advance when the engine wasn't under load (high manifold vacuum). The other provided "venturi" vacuum to approximate engine speed - and therefore govern the usual advance with increasing RPM. It doesn't work very well or reliably either one - and Ford changed to a different system in 1957.

At any rate - if they are working, one of the vacuum tubes would be giving you a steadily increasing vacuum as rpm rises - and the other would behave as manifold vacuum, it would drop with an opening throttle.