The main differences are the scalloped rear end (with accessible deep boot) and the removable targa panel to accommodate open air driving.
The Aeromax strays from traditional Morgan design in that it is only the second fixed head coupe the factory has ever made; the first being the Morgan +4+ which only made it to 28 sold due to a very poor reception, which reflected in low sales. The Aeromax, however, was over subscribed and had a waiting list for people to drop off the waiting list.
Same engine and transmission?
17 left makes the Aeromax very unique.