Michael,
According to the U.S. catalogs, the Team Champion was first offered with Columbus tubing in 1978. In 1977, it came with Reynolds 753 and in previous years, it was offered in Reynolds 531, as was the Le Champion. It was orange in the early years, and then, 'Team' blue and finally 'Brilliant' blue. Green was never an offered color in the U.S. I suspect yours is a European specification bicycle, but is most likely, a Team Champion.
Chuck Brooks
Malta, NY NEUSA