Re:
Just went through the site's archive.
In 1996 the only Mantra was the Mantra Pro.
In 1997 they first listed the Mantra Race, but according to the catalogue it was in "Race Red" only (both main frame and rear section). V-brakes front and back, but a regular Rock Shox Judy.
The 1998 model has a black rear end, not sure about main frame colours. It also has a triple crown fork.
This one is very likely even though the catalogue shows that it had a disc at the front and different fork colour.
In 1999 they drastically changed the pivot area of the rear end, so anything from 1999 on can be excluded.
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Based on that, my calculated guess would be one of these 3 possibilities :
A 1997 with upgraded forks end and a 1998 rear end.
A 1998 that has been retrofitted with V-brakes.
Or maybe something in between (1998 model frame and forks, but built with leftover 1997 components).
Then again I'm no Klein expert.
As for the buying in 2000, that's very possible even if it is a 1997. It wasn't uncommon for high-end bikes to sit in the showroom for a few years.
I clearly remember that in the late 90s my old LBS had the same Super V900 in his showroom for 4+ years.