Here is another solid 40.000 miles 1971 Z28 I looked at last weekend. This one now has a LS7 engine backed up by a M22 trans, but the original LT1 and M21 trans is safe on a pallet. I believe the engine, trans, and rearend had never been apart. The original hood is also in safe storage.
It has the one-piece rearspoiler just like the blue one.
That is a New York state inspection certificate from january 1974, in the windshield.