All depends on which path you take and what you claim an MTB is. This bike took me up plenty of hills and down dales and gave me a ton of off road fun long before 'proper' US derivative MTBs were common place.
Obviously this bike has far more in common with Postman Pat than John Tomac but then the miles I put in on my Vindec off-road definately class it as an MTB in my eyes. Even if you look at the early US MTBs, they were nothing more than bastardised road cruisers.
Chances are I'm not going for this though, it'd be wrong just to buy it for the hell of it, I'd never use it and I'd just feel guilty that I denied it its destiny (to be ridden).
The only bikes I really lust after are those unobtainable ones from when I was a teen. To me, buying this would be like going to Butlins rather than Jamaica on holiday just because that's what I did as a kid!

(that said, doesn't stop me looking at the auction with unnerving regularity and hoping someone nice buys it!)