That's a pic of the retract liner from a Nitro Planes Corsair 50 size ARF. If you could buy the correct size set of these liners for the plane you are doing it might make the installation a little easier to do & would give you a nice clean look when you are done. I would still do the inside lining that Darock & the others are talking about with the sheeting & use these to cap it all off. If they are available, your LHS may be able to run them down for you. Might be worth checking out anyway. Good luck!