More than likely, serial number is just missing the leading "K". I have a 1972 and its still an American Eagle Semi-Pro, while the 1973 I have is a Nishiki Competition. Look up component codes if you desire.

Personally, I treat catalog information skeptically as the specs back then were sent out to printers months ahead of actual production. And with a bike that is around 45 years old, who knows if all the parts are original anyway. I have had several bikes that were not in the catalog for a particular year, and others where the colors were wrong. Parts discrepancies can be as simple as using up old inventory, or getting a better deal between the catalog specs and production.