What size servos does the smaller plane call for? If it calls for standard size servos, like your Kadet does) and you verify that there is room, you can probbaly use them. If not, you may want to look at smaller servos. The only other consideration is weight. Maybe someone else here has built a few .15 size models and can give you a better answer, all of mine have been either .40 and larger or 1/2A.