Thanks for the replies everyone.. It looks like I have several options and it is incredible to me that 3D printed parts is one of them. For now I'm going to re-glue and use a longer screw and washer above the tab to hold the bulb holder to the barrel. I had to grind a little bit of the underside of the cap to accommodate the screw, but I think it is plenty sturdy. Now on to getting the cable to move freely..