Marx liked to make toys based on the latest technology of the day, whether it be concept cars or developmental aircraft, or simply the most updated tech. The De Havilland DH 106 Comet fit the bill nicely. It was the first production jet airliner in the world making its debut in 1952 and Marx introduced their version in 1953 in their #3832 Airport Set. You'll notice in the photos that the plane has rather squared-off windows. Those windows would give the Comet grief in the mid-'50s with a series of highly publicized crashes. It was determined the squared-off corners were causing metal fatigue allowing cracks to appear on the fuselage skin causing the plane to break up in mid-flight. De Havilland's Comet sales never fully recovered from the disasters but the redesigned Comet 2 and 3 versions ended up serving more than 30 years.
Courtesy Wikipedia: https://en.wikipedia.org/wiki/De_Havilland_Comet
One unusual feature is the ring at the tail of the plane. Marx put these rings on a number of toy airplanes. Some speculate they were to be use as Christmas tree ornaments??? Personally I don't buy that theory. I think it was just a means for a youngster to hang his collection of toy airplanes from the ceiling or wherever.
Another unusual feature of the toy is the Air Force Star-&-Bar insignia on the wings. The Comet never entered into United States military service! Were there perhaps rumblings in the aeronautics industry back in the day leading the people at Marx to believe the Comet's would be purchased for Air Force use? We may never know. The plane measures 4 7/8" (12.38cm) L x 6" (15.24cm) wingspan x 1 3/8" (3.49cm) H
Enjoy! Opa Fritz and Oma Bettina