Hello again and thank you both for responding to my query 
To avoid any misunderstanding, the item I purchased was both sealed in it’s original packaging and shrink-wrapped, so it is not a case of a fraudulent eBay seller. The seller sold exactly what was advertised and I received it exactly as described.
As regards support, my local distributor (Yamaha Music Australia) has no ability to alter the Steinberg eLicenser database (a fact I have dealt with in the past) so I contacted this forum web-site as this is exactly what I had to do the last time around (even after having contacted my local distributor).
The substantive issue/problem is that Steinberg sells boxed copies of ‘Nuendo Live’ shipped with a pre-authorized USB eLicenser and the package does not include an authorization code on a card. The problem is that in the case of pre-authorized USB eLicensers, the Steinberg eLicenser database does not (as one would assume/hope) register the date of the first registration to your MySteinberg Account as the actual date of registration and website authorization. It simply uses the date of USB pre-authorization (which I assume is the date that the license was deposited onto the USB prior to it being sealed into it’s packaging).
This leads to the problem that one can never get a Grace Period Update/upgrade on a boxed copy of Nuendo Live (despite the fact that this is stated as being possible on the Nuendo Live webpage). Had I purchased this item on the same day as an electronic download I would not have a problem, as the eLicenser database would register my date of authorization correctly.
Once again, if a Steinberg rep could please get in touch and help process my Grace Period Update for my legally purchased copy of Nuendo Live that would be greatly appreciated. I emailed Nuendo Support yesterday and have not heard back as yet (which is perfectly acceptable, as I would expect it takes a day or two to get back to me). For the sake of other users, I thought I would post my question to the forum in order to get some attention and also to clarify the problem of boxed copies with pre-authorized USB eLicensers.
Kind regards,
George