Re: Old-stye electrical box
I have seen boxes like yours; there was a threaded nipple that screwed into the central fitting/hole in the box and the wires were threaded through the nipple to the fixture. A canopy went over the whole thing and was retained by a decorative nut screwed onto the nipple, or the adapter that accompanied the fixture.
There are small round boxes available that are just slightly bigger diameter, but have the threaded tabs. You need to switch them out.
Remove not the ancient landmark, which your fathers have set.