Triumph TR6R 1970 Seat

I'm restoring my TR6R & am trying to find a seat.The parts manual I have does not list a seat!!So I went looking on e-bay ( Aust,UK,USA sites ) & found seats to fit 64-69,71-76 but nothing for 1970.Does anyone know the correct part number or which style is correct for this year?I would prefer to buy new if possible.
Any info would be a great help.Stretch13.

According to my 1970 book, it is part F11573 (83-1573).

My "Kim the CD Man" 1970 parts book shows exactly what L.A.B. found, illustration on page 52, part number listed on page 53 (illustration item # 32).

Thanks for the info,would have replied sooner but been in Darwin trying to source parts.Much appreciated!!