Cross Ram Manifold

[golfer]

I have recently purchased a 1968 RS Z28 with a cross ram setup. The sellor indicated the cross ram manifold was a prototype he bought in NC from a man who had purchased it in the Smokey Yunick shop auction. I did some more research and the book "Camaro, Untold Secrets" (1991) indicated that the manifold was not only a prototype, but had been run on Penske's Trans AM winning 1968 Camaro.

Now I am wondering what something like this is worth and where I might find a replacement cross ram manifold so that I can take this prototype off the car and save it.