The Bentley T-Series was even more rarely built than the Rolls Royce Silver Shadow. The Bentley being technically an identical twin of the Rolls Royce seems to have been bought mostly by owners wishing a little more understatement. The formerly more sportive image of Bentley motor cars differing from Rolls Royces was gone by the time the Silver Shadow/Bentley T was introduced and thus couldn't motivate buyers any more. The outward appearance of a Bentley T is slightly more dynamic because the bonnet design is a few centimeters lower and the radiator shell shape with its rounded edges is smoother.
The T1 was made from 1967-1977 and the T2 was made from 1977-1980.