I remember the first time I saw a No4 with twin groove rifling: I was certain it was a fake. I know better now haha.

About the metal piece on the front hand guard, I suppose as long as it is still clamping the barrel as intended it wouldn't cause issues. The front sight protectors could cause issues if they buzz around and contact the front sights while shooting, maybe giving a similar issue to what happens when the top hand guard slips forward and contacts the sight.

I may be completely wrong. Its a nice looking rifle. I love the dark stock.