Hi Kempy,
Interesting pieces, and good to hear you have all the bits required for the install. These manifolds are challenging to tune, so it's reasonable to think that someone might have fitted it for a short time then given up on it all thise years ago. They need heaps of ignition advance, custom accelerator pump cams, and a camshaft designed specifically for the characteristics of the engine.
Jay Brown over in the states is the guru of FE intakes. He says the power starts to fall away from 4500rpm compared to the Edelbrock cross ram, but he acknowledges the cool factor for those who want the look and aren't interested in peak performance.
The $2500 intake is a brand new (NOS) intake, so it's hard to get a price reference from it.
As David mentioned, the Australian Cobra crowd isn't really the market you need to aim for. I hope to have an FE motor in my Cobra soon and I love the look of the cross ram, but it won't go close to fitting under the bonnet.
You might want to look at
Network54 or
FE Power to see if anyone in the States is interested and is prepared to pay for shipping.
Take heaps of really detailed photos. Post them here and post them on every ad that you write on forums. You never know who might be searching at the time, and pictures really help.
That said, if the parts are getting in your way and you just want to offload them cheaply to a tight@rse Aussie, I'm your guy!