Abstract: Apparatus in kit form for the assembly of a model rocket having a body tube, fins, and propellant mount, wherein each fin has a root portion at a radially inner-most end for mountingly extending through slots apertured in the body tube and for mounting engagement with the propellant mount. The body tube is apertured with slots for mountingly receiving the root portions of respective fins. The propellant mount telescopically mounts within the body tube and mountingly seats the fin roots. In one embodiment, a plurality of mounting brackets is arranged for assembly with one another for forming the propellant mount. The mounting brackets have radially-extending mounting recesses for engaging and positioning a fin root.