Hi Ng Vi
You might want to ebay PM the seller and mention that the knife is not a Spartan and to query whether he knows anything about the provenance of the knife. Just for interest.
Not worth negative feedback, a return, or a price reduction in my opinion
Because ... You do have a 125 Anniversary model - ie you have the scales and the etched blade.
And at that price - I'd say you have a great deal.
As ICanFixThat said maybe it was made at an event. There are a couple of great videos on youtube of people making their own knives at trade shows
Or maybe it was even made at Ibach during 2009 - As I think you can make a knife after the factory tour.
Its all very interesting!!

PS. I assume it is a 91mm knife - If 84 - It would be a Gourmet.