This commercial aircraft model was modified from Paper Replika A320 to A321 by Zion. He created a 1:100 paper model of Airbus A321 Air Busan, an airliner from Busan, South Korea. Air Busan received its first Airbus A321-200 on January 2011. It has a pair of A321 since March 2012. Zion emailed me right after I post A320 master template, he told me about his plan to do A321. A321 is one of an A32X family, its member are A318 to A320. A321 is very similar with A320 in shape but with longer fuselage (118%).