Difficult cold start

Plugs-wires-points, valve adjustment, timing check: all good ideas. Tune-up parts and technique suggestions in this post. Carb overhaul: another good idea. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

Your points 2 and 3 amount to throwing parts at the problem, which will probably not solve it or help anything, and will just eat up time, effort, and money. The ballast resistor is already bypassed during cranking; you don't have to put in a relay for that.

What is needed is basic diagnosis. Are the carburetor and the fuel line from fuel pump to carb emptying overnight so you have to crank the engine long enough to suck fuel from the tank and fill the line and carb back up with fuel before the engine will start?

Go to the car first thing in the morning, remove the air cleaner, hold the choke open, and operate the throttle. If you do not see a strong, steady shot of gasoline in the carburetor throat each time you open the throttle, the carburetor doesn't have fuel in it (or not much). A carb overhaul and new fuel pump will help, but it has grown difficult to get good-quality new Slant-6 fuel pumps—get an AC 6972, see advice here (and up-to-date eBay page here). If you are tempted to install an electric fuel pump, read this.

Or the fuel pump and carburetor might be fine, but the carburetor is boiling like a teapot after engine shutdown (heat rises), emptying it out overnight. This can be addressed by using the thick (9.5mm) carburetor mounting gasket, making certain your manifold heat control valve is operating correctly and not stuck, and doing the Fuel line mod.

Or the fuel pump and carburetor might be fine and there is enough fuel in the carburetor for a fast morning start, but the choke is not operating correctly. It has to close all the way (even with the air cleaner installed, so one morning go remove the air cleaner lid, press down on the base of the cleaner with your hand, and then open the throttle and look at the choke plate; is it all the way closed?).