RE: E Z Arf Models
Jonny,
For my P51 (new version) I just roughed up one side of the aileron servo with sandpaper, cleaned it up with lighter fluid to degrease it. I didnt bother with the plastic card that is glued to the wing rib, I just epoxied the servo to the balsa wing rib. Then when dry, I added the plastic card servo cover with thin CA.
My P51 is 3 years old and it's never caused me problems.