Charles' site is a great resource, but in this particular case, we disagree about the two-rail track in question. His site identifies it as Hafner. If I am remembering our communication on the subject, he saw a Hafner set with this track in it and that is why he identified it this way. While I don't doubt his story at all, I believe that the preponderance of evidence points toward Marx. Track is easily damaged and likely to be replaced in a set.
But, that isn't meant to take away from his fantastic website. He has done a great job on it!
Typical Hafner track:
