I believe there are one or more threads on the forum that cover this in some detail, so a quick search may turn up some pictures and additional information...
But briefly, they are different in shape somewhat (have different coverage) and I was told that the Morgan optional windscreen has some sort of coating on it to make it more scratch resistant. Additionally, the Morgan screen has a black-out mask around the bottom edge corners. And no doubt there is a difference in price and availability :-)
