I am adding A/C to my Shelby. I hunted down all the factory components. You seem to be going to a lot of trouble to make it look as factory. You would be wasting your time once you bought one of the "kits" out there because it will all be for moot.
The dash center vent isn't reproduced. There is a poor quality plastic center vent unit that doesn't match the dash. You also need a different array of pulleys and mounting brackets. All the underhood A/C parts are reproduced with the exception of the vacuum tree for the manifold, and the original type heater valve, brackets for the compressor, both idlers and the crank pulley.
If you're building with a particular goal in mind you need a well laid out plan. You don't want to do this one as an afterthought. It's a relatively involved job that requires a lot of forethought and a bit of capital. It's not a cheap project and will cost well over the aftermarket kit by the time you restore the components you dig up. The only reason I went to the extremes I did is because I have a real car, and If I'm going to make a change of that significance I wanted it to look as if It came that way.
Just some advice from someone who is actually doing what you're asking about, not just throwing their two cents in.
Kindest Regards, Keith