Does anyone know of a mod to the airfoil for Models I, II, III that is supposed to improve the performance? The Kitfox I am rebuilding has a plastic extrusion epoxied to the leading edge of the wing which causes the leading edge to have a shorter radius, and the front of the wing to be a little bit lower than the original airfoil.

The only thing I have been able to find so far is an article in Sport Aviation which refers to a mod made to a Kitfox III by Murle Williams, based on data supplied to him by Harry Riblett. The mod was said to consist of a piece of 1" PVC sawn in half lengthwise, epoxied to the leading edge, and then faired with something called "Feather Fill". Since I am rebuilding my wings, I wondered whether the mod is worth retaining.