Ah, X-Foil. The object of many of my curses, pleadings, and affection. A program whose convergence depends on the tides and the phase of the moon. Actually, it's really not that bad, and pretty powerful once you figure it out. You can get it here:

http://raphael.mit.edu/xfoil/

Anyways, it does let you pick points using the mouse and forms an airfoil to those points, so if you want just load the 2319 (XFoil has all the NACA 4 and 5 digit series programmed in, so just say NACA XXXX at the command line), and modify away till you get close to the mystery foil. This will be a lot easier then trying to get the mystery foil into Xfoil coordinates.

Dan Nelson