kablair: Your Krag butt plate should have a hinged trap to access the top hole. I'm attaching a picture of a Krag three-piece rod, oiler, and muzzle-cap/front sight protector.
thanks again, I know what they look like, just bought a set - would like a screwdriver and a front sight protector. It is a tight fit - it would appear that the rods must be removed before the oiler can be removed.