2 1/2" X 4" (61mm X 98mm)

(front skirt) BULLERS LTD / LONDON 

  {Bullers}

Picture courtesy Bob Berry

2 1/2" X 4" (61mm X 98mm)

(front skirt) TRADE MARK// 

                   MADE IN ENGLAND

 (rear skirt)        ↑ / GPO    

         {Bullers}

Picture courtesy Bob Berry

2 1/2" X 4" (61mm X 98mm)

(front skirt) TRADE MARK// 

                   MADE IN ENGLAND

(rear skirt)           GPO / 2            

{Bullers}

Picture courtesy Bob Berry

2 1/2" X 4" (61mm X 98mm)

(front skirt incuse)↑ / GPO

(dome top incuse)

                     1940 / No. 8

                     MADE IN ENGLAND

{Bullers}

Picture courtesy Bob Berry

2 1/2" X 4" (61mm X 98mm)

(front skirt inkstamp) SILVERTOWN

{maker unknown}

Picture courtesy Bob Berry