If you are building the FT Simple Scout with the balsa stick rear fuselage, you may find that after gluing in the cross members the stabilizer tabs on the fuselage are slightly off from the stabilizer slots. One way to correct this is to make a spacer from balsa for a better fit. Could be a good idea to have the spacer in place before you glue in the last cross member. It might work with foam board. instead of balsa.