Here's a single new Bullet Door Mirror for the following models from Triumph -

TRIUMPH

Triumph TR4a

Triumph TR5

Triumph TR6

This will fit on either side and can be used on almost any car but will particularly suit the following older ones where the square TEX mirrors look a bit to modern -

This comes complete with the fitting kit, a gasket and two screws -

You will need to drill holes in your door panel to fit this (5cm apart - from the centres of the holes) and insert the screws through the door panel from the inside.

The glass is flat (Not Convex) with an 88mm diameter, the base is 9.1cm long.