Frejus changed names and specs from the 50's/60's to 70's plus they had a habit of not putting model names on their frames. In the 60's the hierarchy was "Supercorsa" "Corsa" and the "Strada". I've found some literature that says the only difference between the Supercorsa and the Corsa was that the frame was chromed on the SC. Later literature says the SC is lighter than the Corsa. Eventually, the Supercorsa became the "Professional". I believe the "Tour de France" model was the new name of the Corsa and the Strada became the "Middleracer". It appears from early literature that Reynolds tubing was only used on the Supercorsa in the early 60's (and even then only frame tubes) and as time went by, it's use became more prevalent. A good indicator of the higher line models is the oval cut-out where the seat tube meets the top tube. They're all extremely cool bikes