GHS:

That's just fine to leave the hand guard alone. It's not easy and takes patience to fool with these. The crack is often a lot worse than it looks when you actually take the hand guard off and see that it is in two or three pieces. You are right that you're fighting the strong retaining clips the whole time and that takes some trickery to work with.

The hand guard crack is only cosmetic. The Krag will shoot just fine with the crack or without.

Keep us informed about your success with your shooting!