Have you ever used the command fit spline? "tools", "spline tools", "fit spline". this will allow you to take 3 splines and make them into one continuous spline. when you make an extrude part you end up with a nice edge with no breaks.
original sketch, made up of three splines, changed to sketch geometry, used the fit spline
then extrude the spline, see the edge on the outside no extra lines where the original splines would have shown an edge.
Thanks a lot Tom! That was exactly what I was looking for!