Howdy folks, I recently purchased a new 1927-A1 from a GunBroker dealer. I am trying to replace the factory rear sight with a new Lyman sight. However the screws on the current sight do not want to move. Are these "peened" from inside the receiver so as to make them difficult to remove? Has anyone had any experience in removing the rear sight screws? At this point I am thinking I will need to take it to a gunsmith to get the new sight put on. Thanks for any advice.