These lamps were OLD and OUTDATED.
Sorry, Mom ... I know they were in style when you bought them 30 years ago.
It was time to do something.
Rather than get rid of them, why not make them work?
I unscrewed the lamps and discovered they were actually two pieces - excellent! So ... good bye to the big bell at the bottom (and the HUGE shades!). Then, my dad cut two circles for each lamp and routed the edges.