True Temper Black Prince dates?

[Curt Hal]

I have been checking out the BLACK PRINCE discussions on this forum and have done some other research. I am lead to believe that any axe marked TRUE TEMPER BLACK PRINCE without the additional name Welland Vale would have been made in 1965 or later. The one I picked up is marked TRUE TEMPER BLACK PRINCE without the name Welland Vale, but has the year 1964 stamped on it. I am assuming its original owner stamped that date on it, along with his initials RFZ (which was stamped, along with the date, on every head in this batch).
My question is, does anyone know if the TRUE TEMPER BLACK PRINCE name might have been included on axes made before 1965? I'm curious to put a more precise date on this one.