Make saure it has an engineers if not your insaurance dont have to pay out if in a crash.A blue slip/pink slip for the change of engine numbers.The easiest way of checking the condition of the engine check the oil, should be clean how dirty will depend on how much /little the change the oil>inturn the general treating of the engine, look for a bad cluth> engauge height.Or load it up, stationary put her in top gear hold the revs at 2000-2500 then eez the clutch out if it stalls the clutch is ok if it free revs the clutch is stuffed>(also check for clutch clutch shudder). Look for crash damage pannels not lining up bad paint work. Get a revs check to make saure the cars stillnot being paid off, PAY CASH BRING HIM DOWN SOME dont forget RTA transfer fees.