Big Ben pens can be quite confusing: there is a modern kit pen that goes by that name, there is a Big Ben that is a sub-brand of Wyvern and finally there is the excellent Danish piston filler.

This is an example of the latter.  The pen is in green marble with black lines and there is a translucent area so that you can check how much ink is left in the pen.  The clip screw, blind cap and section are black.  The nib is marked “Big Ben 14K 585 1” which doubtless means that this is their version of a number one nib, though it seems a little larger than I would expect for that size.  The pencil is marked “Original Big Ben 15” and it works very well.

I find this pen quite hard to date but I suspect that it’s pre-war.  The cap bears the the number 451168, which I astonished myself by being able to find in Espacenet.  It relates to the piston filling system and was written by two Germans, Heinrich Hebborn and Heinrich Schlicksupp, trading as Hebborn and Co., Cologne.  It’s dated 30th of July 1936.

I understand from Paul LeClercq’s troubles and tribulations reported in Fountain Pen Geeks that these pens can be very difficult, or even impossible to repair.  This one is working – for the moment – but I won’t be selling it until I have it checked over by an expert.  Which is not me, I hasten to add, where piston fillers are concerned.