I have a 64 hardtop with no options so my vacuum system may be different, but I can still give you some advice.
The brass fittings that you show in the fitting- if they are original, don't be concerned that you have to connect every port. The largest one looks like it's your PCV system. The next largest (probably 3/8" hose) should go directly to the power brake assist. The third largest (1/4"?) goes through a check valve, then vacuum accumulator, then the firewall into the interior. There it splits to the parking brake release and the two rear deck motors that open that vent. If you have AC then it also feeds the heat and AC controls. If you have power locks then those hare vacuum controlled too. Last, you may have other hoses depending on the options that you have.
The accumulator is so that your power locks work after the engine shuts off. Note the check valve in that line.
Test all these for leaks and fix them. Apparently the previous owner didn't want to so looped the hoses. The engine will run terrible with a vacuum leak.
The vacuum port at the base of the carburetor, passenger side front, should go directly to the distributor vacuum advance.