Your right...the problem is that we are looking at 30 year old paint and trying to figure out what it used to look like. Paint fades...so do 30 year old memories.
I should post some links to all the heated threads on Moparts involving argent paint. I don't think there is ever going to be a clear cut answer. The best we can do is look at NOS stock and try to replicate that as close as possible. I'm sure that even NOS parts are shelf worn and don't look exactly the way they did the day they were sprayed.
I really want to see your car someday Bullitt. Not only because our cars are cousins but because it's nice to see someone who cares to get the details right on the newer Challengers. Most people don't think a single Challenger was built after the 71 modle year.
This is a pic of a survivor 70 Cuda. The picture is of the shaker bubble being held up to the grill. There was some discusion on weather the shakers matched the grills or not.