icraker, There are two backsights marked 'Mk2'. A Mk2 backsight is the two position 'flip' sight. The Mk3 backsight has a slide marked Mk2 and is made of stamped steel. It's a bit confusing at first.
The magazine wasn't originally marked at Maltby and is more likely the result of a field repair, possibly as minor as replacement of a missing or damaged magazine.
The majority of L-E rifles are matching in the US and is preferred.
Brad