BVM Super (Balsa) Bandit
The removable rear nozzle attaches to the fuselage at 4 points - at the top there is a paxolin strip which is screwed and glued to the nozzle, and screwed to the rear of the fus; at the bottom is a carbon fibre s-pin which slides into a retainer on F-8, and we tighten a 4-40 machine screw down to hold it formly in place... and on each side of the nozzle we have a small guide-pin that helps locate the nozzle correctly as well as provide side-ways rigidity.
Here's a side view of the nozzle being slid into place: