Standard Beetles were imported into the US officially until 1977 model year.
Super Beetle sedans were 1971-75. The flat-screened 1302 was 1971-72; the round-screended 1303 was 1973-75.
Convertibles were imported through the 1979 model year. They were all Super Beetles 1971-79.
* * * * * * * * *
US special editions:
Sun Bugs were 1974-only. Sun Bugs were standards with sunroof, Supers with runroof, and converibles in a gold paint scheme. VW imported other 1974 standards, Supers, and convertibles that year as well.
La Grande was a 1975 Super Beetle. It was a special edition but that was the only Super imported into the US. There were standards and convertibles that year. La Grande was advertised as being blue or green but there were gold ones as well. They are often mistaken as being Sun Bugs but if they are a 1975 model, they are not Sun Bugs.
All Super Beetles through 1974 had the steering box. All Super Beetles 1975-79 had rack and pinion. The steering box models had a better turning radius. Rack and pinion was immediately responsive.
http://www.sebeetles.com lists all of the details of these and other special editions through the years of Beetles worldwide.