Exhaust nozzle consist of an inner and outer barrel, rear frame with the afterburner ring rendered and 2 side shield for the 2D exhaust halves. In addition there is an assisting frame used to maintain a round shape when applying the super glue close to the lip.
the parts
Super glue applied
combine the barrels
add the side shields
when done, re insert the shaper frame to just keep it round. No glue at this point.
Technical note:
engine thrust can be controlled and optimized when the nozzle area is controlled at different afterburner condition. Most engines have multiple petals; the entire afterburner nozzle is able to open and close as required. The early french engines used on the Super Mystere and early Mirage 3 had a 2 piece nozzle halves that were simple, however, not efficient.
Isaac