the problem is most of those brands are unattainable
Nonsense! You are just not looking in the right places. Of course, know where the right places are is the trick.
In my little city, I have found a 1971 Masi "Criterium, a top of the line hand built Panasonic, a Saronni, several high end Bianchis, lots of top dog Raleighs, three Miyata 1000 Touring bikes, a near mint 1971 Carlton "Professional", a 1971 Atala "Professional", and many others that I cannot recall at the moment. Actually, I can recall many others, but I do not want to appear to brag.
So, do not snivel just because the perfect bike does not show up on demand. Look for bikes and you will find something to your liking. I do and I can do it almost on demand these days. You just have to know how to look and this is how I do it.
How To Find Vintage Road Bicycles.