When they dissolved the position, I had a few days to try and archive all older e-mail, including confirmed key codes from Nikon.
I KNOW, lesson learned for safekeeping but for the life of me I cannot locate the files I saved, exhaustive search and so on on this now 3 year old machine.
I e-mailed Nikon (JRP mentioned trying that to another thread) and with the four sets of numbers from the log up screen, it took Nikon a few weeks of back and forth wherein they replied OK, we found your receipt and please do not use any old codes, here is a brand new one.
Other than dyslexia entering the code yesterday a few times, everything went well along with a reg clean set of files.
So, Dominican Republic, or El Segundo, whichever solved this, many thanks!