Thanks.
From the Vintage Triumph Register: "The car was never officially called the "TR10," although many have referred to it as such over the years. In fact, Workshop Manuals, Spare Parts Catalogues and sales literature refer to the cars only as the Triumph Sedan or Triumph Estate Wagon. The only references to "10" are found on the car itself: on the Commission number plate (which refers to the Triumph 10HP), and on the front badge."