Yes, it should. The Magpul MBUS sights use an A2 front sight.
Yes, with patience. Hold down the plastic detent and the post will screw in using fingernail or tooth pick to turn post. Detent will only hold the notch in post, not the top part. After sighting in for the right height I carefully, with a tooth pick placed dab of epoxy, not super glue, in the notches of top part and spun it around to spread epoxy and then aligned top part to face rear sight and let it dry. Sounds crazy but with patience it will work. Good luck and good shooting.