Use thin CA for any balsa that you can push tightly together. Use medium CA if there are any gaps or if you are gluing lite ply. For gluing the fusulage doublers use wood glue. Use epoxy to bond the tail to the body and the vertical fin to the horizontal fin. Use epoxy to bond the pine block for the landing gear to the body. You can use baking soday fillets with thin CA to make super strong bonds. Won't sand though. Hope this helps!