Looks good bemfarmer,

I imported the points and they lay right over the curve your program generates. Like you said you still have to work out the radius but I like how you have the curve and then the points to make the radius. The only thing would be on your curve fit it looks like the "through points" option whereas for this curve you want the "control points option". I think you'll see that once you start trying to get the radius in there. The first and last point of the curve will change once you get the radius in there too, since they will become a point tangent to the circle.

But looking good man. thanks