I don't think I've ever heard more than conspicuous jibber jabber and raving of how the "post 64" rifles are junk and the pre-64's are better... so my question is can you list what one should be looking for. �
As I remember it from the time, it wasn't a matter of the earlier being somehow "better" than the later, but a matter of relative values to
collectors.
Then
shooters saw only that the earliers were being sought, and prices rising, and assumed that the issue was quality.