(NOTE: this thread relates to Kitfox models only but may prove helpful retrofitting older Avids as well.)
From time to time there have been questions regarding retrofitting the newer Kitfox Model 4-7 Riblett Airfoil wings to older Kitfox models. Back in the day, Denney Aerocraft actually offered Kitfox Model 4 Control System Retrofit Kit #19065 to do just that. This kit was applicable to Model 2 and 3 aircraft with S/N's less than 1400. Attached are the complete parts list and install instructions, including drawings for Kitfox Model 4 Control System Retrofit Kit #19065.
[EDIT] The Control System Retrofit Kit was often sold with the Model 4 Wing Retrofit Kit #29013. This kit was also applicable to Model 3 aircraft with S/N's less than 1400.
KF 1762 - Model 4 Wing Retrofit Kit #29013.pdf