How to find themanufacturing date when searching for vintage cherry switches

[CMYK]

Hello all,

I've started an ambitious custom keyboard project.  I have searched the forum and other sources about how to identify Cherry MX black switches.  Wyse keyboards seem to be plentiful, but I am really unsure how to find the date of manufacturer on these boards.  Can you tell the date of manufacturer from the serial number of these keyboards?

[chyros]

Usually keyboards are dated with date stamps, such as on labels, on controllers, and in keyboard cases. Serial numbers aren't very date-informative.