I must admit, having climbed all over 385 L42's at Charnwood Ordnance in about 1994 or whenever it was, I never found a rear sight so modified either. However, Peter's comments about the rifle having to go back 'as issued' could explain that. They are easy enough to do - I used a half round file, though one has to proceed carefully. I also used a spare rear sight in each case, rather than alter the originals. There's no doubt that at times it is convenient to be able to slip the bolt out easily whilst on the range.