In 1967 Henry Nyberg, a Swede without any aeronautical credentials homebuilt this, neither legally certified nor registered, aircraft and taught himself to fly. In total he amassed more than a 1000 hours in the Conkubin, with even the propellor being homemade. In 1973, a larger engine and a larger propeller were fitted to improve performance but the only thing that Nyberg would never be completely satisfied with was the plastic canopy.