Mark,
I don't have the blueprint any more, and I don't know whether the course remains intact. The roads appear on Google Earth, but the exact points are unreadable.
I think I'll see what a search for "Shamrock Classic" reveals. Small-town races sometimes last long. I have one here in Upper Arlington that I first measured at least thirty years ago, and it has not changed a jot.
WOO HOO! WAIT!
Just now got an email from son Stu, who was registrar for a few years while we were transitioning from paper to electronic files.
He has found the blueprint! He is pouring concrete today and will send me some full-size scans of the 11x17 inch blueprint.
More when I have more.