Simple job or so I thought it should be. Delta tub spout with the pull up shower divertor. Circa 1980. So pushing 40 years old. Has the hole under the spout that should have set screw of some type inside. No sign of any set screw, either allen or slotted. Used a flashlight and mirror and I can't see anything inside the hole other than the copper pipe with now shiny marks on it from the screwdriver. Could Delta spouts of this era have used one casting for screw on and the same casting for the set screw type? Is it possible that even though there is a set screw hole I have a screw on spout. I am hesitant to really twist on the spout, but do feel like this is a job I should not have to call my plumber for. Is it possible to have a set screw hole with a screw on spout? Thanks.