Possibly one of the last of the three-wheeler Morgans is the 1937 o.h.v. a/c Sports Morgan (in this case a/c means air-cooled not air conditioning). I had the pleasure of meeting Peter Morgan on a couple of occasions, he came into his office wiping his hands on an oily rag, a true working boss.
Do take a look at The Morgan-Motor Company. A really excellent site. Note also that 2009 is the centenary of the Morgan Motor Company.