If its not too far away go have a look , doesn't hurt to look , just make sure its not raining so you can have a look underneath , just check the rear wheel arches , petrol cap area , just generaly all over .
Looks a nice car but they look more like mondeo alloys than cosworth ones so if he's wrong on that account then maybe he could be wrong on what else the cars had
If he's got reciepts then check them out , if he's a member of a forum then maybe he did a rebuild thread check it out , depends how far you want to go .
If i had the money and it was closer i'd like to look at it .