Quote Originally Posted by cradeldorf View Post
I guess I automatically assumed that as they progressed through the years that they no longer made the old models. That's why I figured that a 515 B was an early driver. I was not aware that they continued to make "B" models all the way into the 70's. I was wrong my 604 does have a line through the QC mark. and the cone number appears to be followed by a 3. I do not know whether it's a 64 or 74 other than I figured once they started making the g's h's and k's that they no longer made the E models.
"If" it's the original cone, i'm pretty confident that your 604E is 1974 vintage. 21184-3 would be a late, and perhaps the final revision of that cone.