Hi DAVESS!
This is indeed an interesting question...
In a nutshell, I personnally feel that the choice is one that has both a financial criteria and an authenticity criteria that you will have to come to grips with.
Needless, to say, from my observation, the majority of ERA's have the pin drive with knockoff wheels.
My ERA has the pin drives with knockoffs. I do rather like them.
The wheels are super and extreamly well balanced physically with near zero runout on the latest Hunter wheel and tire balancing computer machine.
The downside of the pin drive is the knockoff and the chance that it can come loose. The safety wire ritual is a must. As are the accurtrements to insure they installed well (Mallet and spinner and wire).
BTW, on another note, you need to contact me and enroll in the New England Cobra Enthusiasts....
Please check out this link here on Club Cobra....
March 2004 NE Cobra Enthusiasts News
Hope to hear from you. If you have any ERA questions I will be willing to help in any way I can. When is your build starting?