tighten down the gear cover screws all the way and itll deform, just back em off a little bit and it will deform less. In a few run the screws wont back out much, just recheck it every now again. a little gap at the top isnt that much of a big deal, with the SC body on it there shouldnt be a single moment that the top of the gear cover is in dirt so its not much to worry about. The slipper button is just something that comes off. When yours does, go take a walk on the track and you will find 4 more.