Hello wrt forum, I have a maybe 80’s automatic mido ocean star.  I bought this as a project.  I haven’t encountered this type of screw back.  There are no flats or indents for tool to grab.  Just a round back with hardly a gap.  I tried the sticky ball but no luck so far.  Has anyone encountered this type of back on a Mido.  Is there a special tool I need to have.  Any suggestions would be helpful. Thanks