Did you leave the rail in the concrete ties while laying them, or did you lay just the tie strip? If the latter, how do you keep the curves smooth?
Although Ed answered this question, I got to thinking about it because it is possible that the ties are not exactly the same size or the attachment points are slightly different, and laying them against a straightedge will make the ends of the ties against the straightedge straight, but the other side??? Maybe not. The attachment points?...Maybe not.
BUT, since Ed is laying code 40 rail into ties that are designed for code 55, there is some slop. Because of that, I think all will be well.
I agree with Gary, "...we are lucky to behold the process."