I'll agree with the others that this appears to have been repainted. The paint looks too brilliant for 40 years old...I have one this is very well cared for and it has a certain patina to the finish. Looking at the head tube front photo I see what looks like some chroming that extends beyond the lugs...perhaps the lugs were re-chromed and then the frame painted and the lugs were not masked just right?.
Does anyone have a sliver Cinelli with a red-painted serial number?
A 1970 would not have brazed on BB cable guides, by 1972 they did (I don't know about 1971).
Angel Garcia
Long Valley, NJ