Advert reads all wrong.
Good history file = not full service history.
Derestricted air box, derestricted centre exhaust pipe = doesn't know what it is. He's selling it on behalf of a member of staff, surely the employee knows what's on the car?
No warranty = the guy wants no comeback on it. However, hold on this is a dealer advert. Dealers give an implied 6 months warranty under the sale of goods act...
All cars over £1,000 come with 12 months warranty = contrary to the above, probably a cut and paste from his standard adverts. Warranty needs clarifying before you go anywhere near it.
In short, alarm bells are ringing for me. It might be straight, but no mention of a HPI check in the ad. The guy is a dealer, HPIs are bread and butter and it sounds like the "selling on behalf of a member of staff" story is made up so he can get out of offering what he should be doing as a car dealer.
Personally, I'd avoid it.