I have a Carmine Red striated Lifetime Balance with a two-tone nib which I believe is from the late '30s. The nib is engraved with "G64473" at the tip-end of the nib. I point this out because I've seen some Balances with the code stamped at the section-end. Is this some kind of serial number, a date code for the nib, or something that will tell me about the entire pen's manufacture?

Thanks in advance!

Dale