This difference in feel between your old 72 4/4 (I owned a 72 4/4 for four or five years) and your current +4 could be due to the master cylinder bore size although there's not much you can do about.
Titus, can I suggest this: stick your head down into the footwell and depress the brake pedal. Try and determine how much 'free' movement there is before you meet pedal pressure. A lot of movement may mean poor adjustment.
I can't speak for your car, but Morgans generally have an adjustable pushrod with a clevis bracket and spilt pin that fastens the pushrod to the brake pedal. If you have excess movement and it needs adjustment, this is one possible area for a solution.
