the crown is too large, and the crown guards are too short, it'll never look right because of the cgs. the gen in the picture has a 702 crown strong beveling makes it look larger than it really is, youd most likely end up with a 703 since a gen 702 tube is impossible to get.
IMO youd replace the insert on both the MBK and this new one. gen inserts snaps in on the mbk perfectly and sits recessed. dial is better than the 5513 MBK stock one from what i can see. lug holes seem to be a bit high, and will probably need widening