I have those late type BO masks on my Tilly and Morris Commercial. Mine were made by Butler and don't have the additional lens in the flap. You can at least use these at night with a degree of illumination. Ron
That's right Lex. The British army seemed to often fit the old Butler tractor lamps. They even went as far as changing the nice sealed beam headlamps in Jeeps in favour of the Butler lamps. Simply I guess so that the standard bulbs could be used. Ron