There were several variations of the emergency Bren made so why not several variations of the emergency rifle - if it is indeed such a beast? As for utilising some of the parts of the standard rifle, then surely, that's the whole point! Even the emergency Bren used many standard parts.

From an engineering point, then it is clearly FAR simpler to make/fabricate. You machine a simple butt socket end with the locking lugs then you machine a relatively simplebreeching up threaded area then join the two together around a simplified mag housing. Ater all, that's how the real McCoy is made up, albeit in one piece. I wouldn't mind betting that the nose cap is a wrapped and folded fabrication too. In fact, I'm going to put my money on it - and £20 to any Forces charity if it turns out to be wrong