The red size stamp should be inside the bell. The black hand stamp or the embossed Paiste logo? Serial numbers started about 1971.Yes... the Sound Creation line started in 1976, the embossed logo was round and the hand stamped Paiste logo was black. It sounds like you have two very rare cymbals. Can you post a photo?
I don't have the 602 yet! The Soundcreation is in the studio with my kit. I'm going to see the 602 this week, & will try & post photos asap....thanx...mike