U can buy a ring similar to that without the teeth on the ring. I had to replace mine so I purchased a lookalike and then used a "toothed" washer to secure the unit.
Do a little searching around with your computer. I found this pretty quickly. https://www.waytekwire.com/item/30087/Molex-19074-0004-Star-Ring-Terminal-22-18-AWG-/
That isn't a ground strap, it's the ring terminal that grounds to the upper A/C compressor bracket? The ground strap is at the bottom of this page, http://www.diecastmusclecars.com/buick_battery_cables.htm