Thanks again for the all the comments. I did some more measuring, and put it up against some of my other bikes.
It is clear that Lemond measured center to center. And it is clear that it has a relatively long top tube and effective head tube length.
When you compare to my 58x57 ironman it really is pretty close (I think both centurion and schwinn meausred to the top, so there is 1.5 cm right there). I put them side by side, and the biggest difference between the bikes is that the top tube is just a bit lower compared to what you would expect on a bike that size( with a horizontal top tube).
So as I said before, I am going to keep this for a while. I think I will trade for the 57 should one become available. But until then I see no reason not to keep this one.
One more thing, this bike is very light. It really is a nice bike