As years went by the basic design of the PA-18 was improved, many experimental as well as certified kits appeared on the after market and better power plants capable of delivering between 140 and 180 HP were installed, giving this aircraft its well-known behaviour in the realm of really short takeoffs and landings. Copycats, imitations and similar aircraft were developed among its lines - the Aviat Husky being just one example - and after some years, PA-18 were even being manufactured by other companies other that Piper - like Cub Crafters - entirely on their own.
"The instrument panel in the cockpit of a PA-18.
Some versions of the Super Cub are significantly different in structural terms from others; such is the case of the PA-18A, designed specifically to be a cropduster. This model doesn't have the "backbone", which is a strut that goes all along the back top of a Cub fuselage. In the case of the agro PA-18, the back is totally flat.
In this picture of a PA-11 you can clearly see the backbone of all Cub fuselages, except those of PA-18As.