There were more than 2 versions of the L-4. The original designation was 0-59, changed in 1941. The first 0-59's had either a 45 hp Franklin flat-four or a 50 hp Lenape Papoose 3 cylinder radial, and when the Army ordered the newer J-3 with the 65hp Continental, it became the L-4A, due to a change in designator (O for Observation became L for Liaison). The L-4B had different radio gear, the L-4H was essentially the same as the B, the L-4J had a variable pitch prop; the L-4C and D were civilian Cubs pressed into service as trainers and US coastal patrol, and did not have the "greenhouse" canopy. The Navy also used this model for trainers, designated NE-1 and later NE-2.

Individual markings are dependent on the theatre and time of service. One popular marking is the roundel star with a yellow band around the roundel. This was specific to Operation Torch, the North Africa Campaign in 1942 (43?) By far the most popular markings are the "D-Day Stripes" on mid span wing and rear third of the fuselage. These did not appear before 5 June 1944, as they were hastily painted on all Allied aircraft the night before the Normandy Invasion. (I find it interesting that when you see a restored plane with these stripes, or a model of one, the stripes are all neatly masked and even. In reality, they wer put on with whatever ground crews had on hand at the time, usually house paint and a wide brush, and only looked "good" from quite a distance)

Other versions of the L-4 were not actually modified J-3's; the L-4E was a J-4E Club Coupe, with a 75hp A75-9 Conti engine, wheel pants fully enclosed cowl and longer wingspan. The J-5 Cruiser followed as the L-4F (75 hp J-5A) and the L-4G (100hp J-5C). The Navy bought 100 of this model and had them modified with a hinge-up turtledeck which could carry a single stretcher patient; these were called HE-1, renamed AE-1 when the H designator was given to helicopters. In 1945, the Army ordered another ambulance version, of which only five were built before the contract cancelled at the end of the war. It was the L-14, which could carry 2 litters stacked one above the other behind the pilot, and had a 125hp Continental 0-290-C equipped with electric start and fully cowled engine. It had side-by-side seating in the front, and a second passenger in the rear if no litters were aboard. It was also the first Piper airplane with flaps; it is surely the immediate predecessor to the PA-12 Super Cruiser.

There was even a version of the J-3 with the engine removed, as well as the standard landing gear, which was replaced by a straight axle without suspension, and a rounded nose where the engine was. Called the TG-8, it was a glider trainer, and could be towed aloft by a J-3. And finally, the L-4 was reborn in Korea as the L-18.

"Grasshopper" is actually a generic term applied to most of the small liaison / observation aircraft in use during WWII. L-2 Taylorcraft (0-57), L-3 Aeroncas (0-58) also were referred to by this name. I hope this isn't T.M.I. but I did a lot of reading when I built my L-4, and found the Cub's history fascinating. One of the most interesting items i found were brief notes and a single picture, of L-4's mounted with bazookas (up to 3 on each wing strut), several of which are credited with tank kills. I modeled this on mine, with one under each wing on the struts.