Carb Problems: Holley 1920:

The carbon canister holds fuel vapors until a high vacuum situation arises (you chop the throttle) and the vapors are sucked into the intake instead of polluting the air.
OSAC valve? No clue. Sounds like something to throw away.
Photo 1 item 1 is the vacuum port for the exhaust gas recirculation valve (EGR). Photo 1 item 2 is the EGR valve.
Photo 1 item 3 looks to me like you should move the throttle cable to the link currently occupied by the kickdown linkage. The linkages are crossed and should be parallel.
Photo 2 item 1 should have a tab under the choke pull off cover bolt for the return spring. If what you have is working, don't get in a lather about it.
Photo 2 item 2 is the ported vacuum for the distributor advance. You need to run a line from there to the vacuum advance on the distributor. Lose the vacuum advance line you now have and plug the source. Early smoggers don't like manifold vacuum for advance.
Photo 2 item 3 is the bowl vent that runs to the carbon canister. If you don't have a carbon canister, don't worry, just plug it off. Carb will still vent and operate.
The biggest problem I see in these photos is the wire running to the choke pull off is not connected. This wire needs a 12v source to open the choke, preferably one that has 12v when the ignition is on.
Hope this helps.