Its not my knowledge, its just stuff I've learnt from people like Peter Laidler and Kev Groom, they are the real Bren gurus. I have very little knowledge of my own to give, I'm finding out new info from serial number, i.e. variations and numbers of. But thats about it.
I have very recently discovered somthing that has never been published before about the STEN gun. Its really trivial but to a STEN collector its another bit of info. that is that the STEN Mk1 Butt (Butt STEN No2. Mk1) was produced by Unique and Unitly cycle (Marked U&U), They then went on to produce the STEN Mk2 and Mk3 Butt (Butt STEN No2. Mk2). Previously it has never been record (AFAIK) that U&U produced the No.2 Mk1 butt, and they must have been making them along side the No.2 Mk2 butt as I recently sold an example of a No.2 Mk1 butt with the U&U logo and I have an example of a No.2 Mk1 butt, also with the U&U logo. The latter butt used the Mk1 abutment plate (a Casting), modified by grinding off the bottom tube lug. Now I know some will say that they probably just used up existing stock of Mk1 parts, but I also have a Mk1 butt which has the wartime code M255 which was used to replace the U&U logo, later in the war, so the butts were produced along side each other, along with guns.