I maybe punching above my weight with this one, I think to do it properly it'll end up at least 3ft x 3ft, so lots more barrels to cast.
The tubes are to look like heat dispersal pipes for the exhaust.

Mid to late 1970 was when the then Soviet Union was equipping various insurgency groups with Strela-2 MANPADS. First generation of serious heat seekers, that generally locked in on the exhaust/tail pipe. The Rhodesian Air-force, with it's limited access to international markets, due to the UK gov getting the UN to imposes sanctions, produced 'in-house' solutions. It's effectively a long extension pipe attached to the exhaust (which normally puffs out just to the side of the engine), that sits inside another wider pipe. Airflow cools the gases and the extra length also has the benefit of shifting the heat spot away from the engines.
They also fitted similar shielding to their Alouette III helicopters. My understanding is that no aircraft fitted with this system was ever hit by a SAM (flying at 500ft probably helped avoid lock on as well).
Not so lucky their civilian airliners, two of which were shot down.
