I live just down the road a bit from Oakland where op is from. Never ever have I used or needed a choke to start any of my old carb'd cars. Temperatures almost never hits freezing levels around here. In fact have always had chokes disabled. Of course all bets are off if I go up into the mountains in the wintertime.

Still suspect dry fuel bowl or accelerator pump as in my original post. Accelerator pump is a long shot as op says runs well when it does start and engine warms up.

Again, pull air cleaner and have a look see into carb while pumping gas pedal after car has sat for a while and won't fire off.