Josh Bixler actually built a twin mustang about 4 years ago. There's a forum discussion about it linked below. It's basically just two FT Mustang fuselages and a mustang wing with a rectangular wing section between them and a rectangular piece for the horizontal stabilizer/elevator https://forum.flitetest.com/index.php?threads/ft-f-82-twin-mustang-is-it-real.9626/