There are a number of pointers to look for, it all depends on how original the car still is etc. My harrier site is down at the moment possibly server maintenance, but it will be back online soon as this has happened a few times before.
As already mentioned, the spare wheel bracket position, but anyone can fit one of those. It should have Triplex Bronze glass all round, and depending on how close to original spec it still is :-the brake check warning system, sports clocks, remote drivers mirror, carello headlamps, ford spotlamps, Altissimo rear light units and foglamp. front and rear overriders, front quarter bumpers, 3 spoke steering wheel, sports gearknob, etc. The chassis number should always start BBAT on a harrier and is usually followed by WP or AB or AA, there are a few later ones registered as W, but almost all were V reg, hope this helps.