Double crest stamping on Cinelli bars was concurrent with the ornate "giro" and "Del Mondo" styles. Also seen on Model 63 from time to time. Maybe others as well.
Unannodized bars are earlier, annodized bars varied quite a bit in finish appearance, can be from material variations, pre anno finishing and annodizing procedures, all can change the outcome. Some appear quite "clear" others very dull and or opaque as a possible description.
John Jorgensen
Torrance Ca USA