didn't come along until later in 2008, so you're looking at the Cooper S with the dealer-fit tuning kit (which as you say is 192bhp). As you've also found, if you enter the registration into MyCarCheck or similar, a factory JCW
will show up as model "John Cooper Works" whereas a Cooper S shows up as, well, exactly that - a Cooper S.
also comes with the body kit, JCW
wheels, bigger brakes etc. as standard, which the S wouldn't. Would also have no Cooper S badge, just a JCW
one on the right, with the front one on the lower grille (not the upper one). You'd also get dark headlining and a little chequered flag on the passenger side of the dash.
That isn't to say the car hasn't been otherwise fettled up to 208bhp (perhaps even with the kit, wheels, brakes and so on - although still 3bhp shy of the factory car), but you're definitely not getting the full story - I'd say, "walk away!"