Scrivy,
The car that is in PA is a very early one and is actually almost entirely different from the current spec car.
That chassis works quite well indeed but it is not what would be built today.
About the only things that have not changed are the pickup points and the basic chassis structure.
The current specification utilizes pull-rod rear damper and anti-roll bar actuation and this system is just one of the many other differences in the various fabricated parts.
For photographic details on the current spec chassis you need to go to
Chassis Photos