I T-eed a vacuum hose from both carbs to the original/standard distributor's vacuum advance (it looked nicer than just using a line from one carb).
vacuum hose plumbing I hooked up the electric choke on both carbs.
My electricals were 6v and the chokes worked fine with that.
The chokes were both powered with a hot lead through an oil pressure switch.
pressure switch - could be placed on a T on any convenient oil filter line I did not use a "progressive setup", I used Tom's very nice linkage kit. The carbs themselves are progressive two barrels.
Langdon's linkage 
