As a future tip, don't apply subsurf unless you have to :P As for the creases in the center, before subsurf applied, add an edge loop close to the center, and that will fix the creasing issues your having - this is caused by subdividing triangles btw :P Hope this helps :)

use ctrl r to make edge loops, you can roll the mouse up and down to select how many, if you only make 1 you immediately go into edge slide mode after clicking. So you would just ctrl r, left mouse click, then type .9 or -.9 depending on which direction to pull the new loop towards the center. Or just move the mouse there, but dont put it all the way into the center. Overall a nice model! I love the attention to detail with the handle and fastners n such.