Website for determining age of Mamiya RB67 lenses?

Is there a website that can tell me, based on the serial number, how old my lenses are? I am selling a couple, and would like to give a prospective buyer an approximate age. One of them is a 65mm f/4.5 without the "C" designation. It's S/N is 14364.

Thanks!

Thank you. This tells me that my lens was probably the "original" and made in the 1970s.