Brake Fade Issues

Brake fade and pedal to the metal (going down to floor) are two completely different things.

Brake fade is overheating the lining and drums until they won't stop. If you had a problem that caused brakes to drag (like a stuck cylinder) they can glaze and cause fading, or even poor braking cold

Pedal going to the floor or leaking down is either shoes out of adjustment, air in the lines, or master cylinder seals leaking internally, "past each other." The classic leaking master is you push fairly "sharp" and it will brake, but if you gently "let off" pressure and apply light pressure, it will slowly sink to the floor.

Rusty fluid? Might be able to flush on a newer car, but on girls this old you may have OTHER problems like rusting lines, rusting cylinders etc. Time to tear the thing apart and see what is there

After all, it is your life and the lives of others, here......................