For a complete list of updates to ERA cars, go here
www.erareplicas.com/427/faqs.htm#usedcars
It will tell you at what car # the various updates occured.
Also, I suggest that you read everything on ERA's website. It is truly the single largest source of information (other than this site) I have found.
BTW, all cobras look excellent to me as well. However, they really are very different. The more you look at them, the more glaring the differences become, and you will discover that you like some more than others- even if you really do like them all.