Uhhhhh, don't you know sir (looks around nervously)
The Army had them removed because they were restricting a soldiers view in a lot of situations. Affecting his/her situational awareness. I prefer the new version, that's what we were issued this last time. Affected a lot of peoples driving and what not....
With all surplus different production runs can be slightly different, as a collector of British kit I know this happens often, so long as what you buy is what it was described to be it makkes little difference but for certain looks you have to ask your seller the right questions