On my plug, the numbers are stamped on the white plastic connector right where the yellow wires enter. They are stamped into the plastic connector, little hard to read at least for us old folks. I just connected my Zumo to that connector even though I have had the plug sitting around for about a year. I procrastinate.
'09 R1200GS - Namibia Orange
'04 BMW R1150RT - Silver (Traded in)
'97 BMW R850R (Gone but not forgotten)