Hey all, I was looking at a USP full size 45 and the guy who is selling it has an extra recoil spring assembly for it as a backup. My question is, is there any reason not to sell that assembly if I pick up the pistol? The gun is barely used and I've never heard of that assembly going bad on a USP before, and that part can gather a pretty penny (as just about all HK parts do). What say you, is there any real good reason to keep it?