bentley r-type continental fastback estimated to sell for around £ 200,000 by auctioneers but ended up being sold for £ 739,212 - a record for the auction house .
originally commissioned by welsh racing driver r d weatherall and painted in his racing colour of purple - the license plate still bears his initials .
the rare bentley needs a full restoration after it was allowed to gather in a barn over the past 15 years .