That is completly wrong information on the car.
It is a 1957/58 Rolls Royce Silver Wraith, Body by Park Ward. Chassis is HLW-16.
This car was the property of the British High Commission from new, and the car was the High Commissioner's car. it was delivered to Karachi and then moved to the High Commission in Rawalpindi and finally Islamabad.
It was auctioned in Islamabad about 1972 by the British High Commission, and the car was bought by someone from Lahore, it seems to have had a few owners from its sale by the High Commission in 1972.
As for the point that Rolls Royce will not allow anyone to work on the car, that is completly misleading and untrue. RR couldn't careless who works on the car or not, it is upto the owner and no one else.