1964 dart brake problems..

Well these cars are as basic as you can get, some random comments

If the drums are worn bad or have been turned (maybe more than once) the shoes won't have the same curvature as the drums and will be, in effect, diametrically smaller. This means only the center area of the shoe will fit the drum, and not only will the pedal feel less hard, but you will have less braking surface, and that small surface, in trying to do "all the work" will glaze and then you will have LESS braking.

So far as stuck cylinders, all you can do is take it one step at a time and see what you have.

When bleeding, start at the furthest cylinder from the master, likely the right rear (pass side).

If you think the air is out and don't have enough pedal, temporarily adjust the shoes up tighter to see if it improves the pedal. Properly operating old school drum brakes should have what amounts to a "rock hard" pedal